Merge branch 'master' into testing

64 files changed, 3779 insertions, 1124 deletions

diff --git a/.eslintrc.json b/.eslintrc.json
index db8ff1fa..8882cb42 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -87,6 +87,8 @@
                 "stringReverse": "readonly",
                 "promiseTimeout": "readonly",
                 "parseUrl": "readonly",
+                "areSetsEqual": "readonly",
+                "getSetIntersection": "readonly",
                 "EventDispatcher": "readonly",
                 "EventListenerCollection": "readonly",
                 "EXTENSION_IS_BROWSER_EDGE": "readonly"
@@ -106,6 +108,7 @@
         },
         {
             "files": ["test/**/*.js"],
+            "excludedFiles": ["test/data/html/*.js"],
             "parserOptions": {
                 "ecmaVersion": 8,
                 "sourceType": "module"
diff --git a/.gitattributes b/.gitattributes
index 2000050e..cb9d99bb 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1 @@
-tmpl/*.html text eol=lf
+*.handlebars text eol=lf
diff --git a/README.md b/README.md
index 631f5a8b..bf217679 100644
--- a/README.md
+++ b/README.md
@@ -156,6 +156,7 @@ Flashcard fields can be configured with the following steps:
     `{cloze-prefix}` | Text for the containing `{sentence}` from the start up to the value of `{cloze-body}`.
     `{cloze-suffix}` | Text for the containing `{sentence}` from the value of `{cloze-body}` to the end.
     `{dictionary}` | Name of the dictionary from which the card is being created (unavailable in *grouped* mode).
+    `{document-title}` | Title of the web page that the term appeared in.
     `{expression}` | Term expressed as Kanji (will be displayed in Kana if Kanji is not available).
     `{furigana}` | Term expressed as Kanji with Furigana displayed above it (e.g. <ruby>日本語<rt>にほんご</rt></ruby>).
     `{furigana-plain}` | Term expressed as Kanji with Furigana displayed next to it in brackets (e.g. 日本語[にほんご]).
@@ -175,6 +176,7 @@ Flashcard fields can be configured with the following steps:
     `{cloze-prefix}` | Text for the containing `{sentence}` from the start up to the value of `{cloze-body}`.
     `{cloze-suffix}` | Text for the containing `{sentence}` from the value of `{cloze-body}` to the end.
     `{dictionary}` | Name of the dictionary from which the card is being created.
+    `{document-title}` | Title of the web page that the Kanji appeared in.
     `{glossary}` | List of definitions for the Kanji.
     `{kunyomi}` | Kunyomi (Japanese reading) for the Kanji expressed as Katakana.
     `{onyomi}` | Onyomi (Chinese reading) for the Kanji expressed as Hiragana.
diff --git a/ext/bg/background.html b/ext/bg/background.html
index 44abe8fd..afe9c5d1 100644
--- a/ext/bg/background.html
+++ b/ext/bg/background.html
@@ -20,6 +20,7 @@
 
         <script src="/mixed/js/core.js"></script>
         <script src="/mixed/js/dom.js"></script>
+        <script src="/mixed/js/japanese.js"></script>
 
         <script src="/bg/js/anki.js"></script>
         <script src="/bg/js/anki-note-builder.js"></script>
@@ -29,6 +30,7 @@
         <script src="/bg/js/clipboard-monitor.js"></script>
         <script src="/bg/js/conditions.js"></script>
         <script src="/bg/js/database.js"></script>
+        <script src="/bg/js/dictionary-importer.js"></script>
         <script src="/bg/js/deinflector.js"></script>
         <script src="/bg/js/dictionary.js"></script>
         <script src="/bg/js/handlebars.js"></script>
@@ -37,6 +39,7 @@
         <script src="/bg/js/options.js"></script>
         <script src="/bg/js/profile-conditions.js"></script>
         <script src="/bg/js/request.js"></script>
+        <script src="/bg/js/text-source-map.js"></script>
         <script src="/bg/js/translator.js"></script>
         <script src="/bg/js/util.js"></script>
         <script src="/mixed/js/audio-system.js"></script>
diff --git a/ext/bg/css/settings.css b/ext/bg/css/settings.css
index d686e8f8..6344bd38 100644
--- a/ext/bg/css/settings.css
+++ b/ext/bg/css/settings.css
@@ -235,6 +235,43 @@ html:root[data-operating-system=openbsd] [data-hide-for-operating-system~=openbs
     display: none;
 }
 
+.dict-details-container {
+    margin: 0.5em 0;
+}
+
+.dict-details-toggle-link {
+    cursor: pointer;
+}
+
+.dict-details {
+    margin-left: 1em;
+}
+
+.dict-details-table {
+    display: table;
+    width: 100%
+}
+
+.dict-details-entry {
+    display: table-row;
+}
+
+.dict-details-entry+.dict-details-entry>* {
+    padding-top: 0.25em;
+}
+
+.dict-details-entry-label {
+    display: table-cell;
+    font-weight: bold;
+    white-space: nowrap;
+    padding-right: 0.5em;
+}
+
+.dict-details-entry-info {
+    display: table-cell;
+    white-space: pre-line;
+}
+
 
 @media screen and (max-width: 740px) {
     .col-xs-6 {
diff --git a/ext/bg/data/default-anki-field-templates.handlebars b/ext/bg/data/default-anki-field-templates.handlebars
index 0442f7c5..6061851f 100644
--- a/ext/bg/data/default-anki-field-templates.handlebars
+++ b/ext/bg/data/default-anki-field-templates.handlebars
@@ -158,4 +158,8 @@
     <img src="{{definition.screenshotFileName}}" />
 {{/inline}}
 
+{{#*inline "document-title"}}
+    {{~context.document.title~}}
+{{/inline}}
+
 {{~> (lookup . "marker") ~}}
\ No newline at end of file
diff --git a/ext/bg/data/dictionary-index-schema.json b/ext/bg/data/dictionary-index-schema.json
index 9311f14c..09cff711 100644
--- a/ext/bg/data/dictionary-index-schema.json
+++ b/ext/bg/data/dictionary-index-schema.json
@@ -30,6 +30,22 @@
             "description": "Alias for format.",
             "enum": [1, 2, 3]
         },
+        "author": {
+            "type": "string",
+            "description": "Creator of the dictionary."
+        },
+        "url": {
+            "type": "string",
+            "description": "URL for the source of the dictionary."
+        },
+        "description": {
+            "type": "string",
+            "description": "Description of the dictionary data."
+        },
+        "attribution": {
+            "type": "string",
+            "description": "Attribution information for the dictionary data."
+        },
         "tagMeta": {
             "type": "object",
             "description": "Tag information for terms and kanji. This object is obsolete and individual tag files should be used instead.",
diff --git a/ext/bg/data/dictionary-term-meta-bank-v3-schema.json b/ext/bg/data/dictionary-term-meta-bank-v3-schema.json
index 1cc0557f..8475db81 100644
--- a/ext/bg/data/dictionary-term-meta-bank-v3-schema.json
+++ b/ext/bg/data/dictionary-term-meta-bank-v3-schema.json
@@ -13,13 +13,71 @@
             },
             {
                 "type": "string",
-                "enum": ["freq"],
-                "description": "Type of data. \"freq\" corresponds to frequency information."
+                "enum": ["freq", "pitch"],
+                "description": "Type of data. \"freq\" corresponds to frequency information; \"pitch\" corresponds to pitch information."
             },
             {
-                "type": ["string", "number"],
                 "description": "Data for the term/expression."
             }
+        ],
+        "oneOf": [
+            {
+                "items": [
+                    {},
+                    {"enum": ["freq"]},
+                    {
+                        "type": ["string", "number"],
+                        "description": "Frequency information for the term or expression."
+                    }
+                ]
+            },
+            {
+                "items": [
+                    {},
+                    {"enum": ["pitch"]},
+                    {
+                        "type": ["object"],
+                        "description": "Pitch accent information for the term or expression.",
+                        "required": [
+                            "reading",
+                            "pitches"
+                        ],
+                        "additionalProperties": false,
+                        "properties": {
+                            "reading": {
+                                "type": "string",
+                                "description": "Reading for the term or expression."
+                            },
+                            "pitches": {
+                                "type": "array",
+                                "description": "List of different pitch accent information for the term and reading combination.",
+                                "additionalItems": {
+                                    "type": "object",
+                                    "required": [
+                                        "position"
+                                    ],
+                                    "additionalProperties": false,
+                                    "properties": {
+                                        "position": {
+                                            "type": "integer",
+                                            "description": "Mora position of the pitch accent downstep. A value of 0 indicates that the word does not have a downstep (heiban).",
+                                            "minimum": 0
+                                        },
+                                        "tags": {
+                                            "type": "array",
+                                            "description": "List of tags for this pitch accent.",
+                                            "items": {
+                                                "type": "string",
+                                                "description": "Tag for this pitch accent. This typically corresponds to a certain type of part of speech."
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                ]
+            }
         ]
     }
 }
\ No newline at end of file
diff --git a/ext/bg/data/options-schema.json b/ext/bg/data/options-schema.json
index d6207952..da1f1ce0 100644
--- a/ext/bg/data/options-schema.json
+++ b/ext/bg/data/options-schema.json
@@ -105,7 +105,11 @@
                                     "customPopupCss",
                                     "customPopupOuterCss",
                                     "enableWanakana",
-                                    "enableClipboardMonitor"
+                                    "enableClipboardMonitor",
+                                    "showPitchAccentDownstepNotation",
+                                    "showPitchAccentPositionNotation",
+                                    "showPitchAccentGraph",
+                                    "showIframePopupsInRootFrame"
                                 ],
                                 "properties": {
                                     "enable": {
@@ -227,6 +231,22 @@
                                     "enableClipboardMonitor": {
                                         "type": "boolean",
                                         "default": false
+                                    },
+                                    "showPitchAccentDownstepNotation": {
+                                        "type": "boolean",
+                                        "default": true
+                                    },
+                                    "showPitchAccentPositionNotation": {
+                                        "type": "boolean",
+                                        "default": true
+                                    },
+                                    "showPitchAccentGraph": {
+                                        "type": "boolean",
+                                        "default": false
+                                    },
+                                    "showIframePopupsInRootFrame": {
+                                        "type": "boolean",
+                                        "default": false
                                     }
                                 }
                             },
diff --git a/ext/bg/js/anki-note-builder.js b/ext/bg/js/anki-note-builder.js
index d0ff8205..244aaab8 100644
--- a/ext/bg/js/anki-note-builder.js
+++ b/ext/bg/js/anki-note-builder.js
@@ -17,11 +17,12 @@
  */
 
 class AnkiNoteBuilder {
-    constructor({renderTemplate}) {
+    constructor({audioSystem, renderTemplate}) {
+        this._audioSystem = audioSystem;
         this._renderTemplate = renderTemplate;
     }
 
-    async createNote(definition, mode, options, templates) {
+    async createNote(definition, mode, context, options, templates) {
         const isKanji = (mode === 'kanji');
         const tags = options.anki.tags;
         const modeOptions = isKanji ? options.anki.kanji : options.anki.terms;
@@ -35,7 +36,7 @@ class AnkiNoteBuilder {
         };
 
         for (const [fieldName, fieldValue] of modeOptionsFieldEntries) {
-            note.fields[fieldName] = await this.formatField(fieldValue, definition, mode, options, templates, null);
+            note.fields[fieldName] = await this.formatField(fieldValue, definition, mode, context, options, templates, null);
         }
 
         if (!isKanji && definition.audio) {
@@ -60,7 +61,7 @@ class AnkiNoteBuilder {
         return note;
     }
 
-    async formatField(field, definition, mode, options, templates, errors=null) {
+    async formatField(field, definition, mode, context, options, templates, errors=null) {
         const data = {
             marker: null,
             definition,
@@ -69,7 +70,8 @@ class AnkiNoteBuilder {
             modeTermKanji: mode === 'term-kanji',
             modeTermKana: mode === 'term-kana',
             modeKanji: mode === 'kanji',
-            compactGlossaries: options.general.compactGlossaries
+            compactGlossaries: options.general.compactGlossaries,
+            context
         };
         const pattern = /\{([\w-]+)\}/g;
         return await AnkiNoteBuilder.stringReplaceAsync(field, pattern, async (g0, marker) => {
@@ -83,6 +85,70 @@ class AnkiNoteBuilder {
         });
     }
 
+    async injectAudio(definition, fields, sources, optionsContext) {
+        if (!this._containsMarker(fields, 'audio')) { return; }
+
+        try {
+            const expressions = definition.expressions;
+            const audioSourceDefinition = Array.isArray(expressions) ? expressions[0] : definition;
+
+            const {uri} = await this._audioSystem.getDefinitionAudio(audioSourceDefinition, sources, {tts: false, optionsContext});
+            const filename = this._createInjectedAudioFileName(audioSourceDefinition);
+            if (filename !== null) {
+                definition.audio = {url: uri, filename};
+            }
+        } catch (e) {
+            // NOP
+        }
+    }
+
+    async injectScreenshot(definition, fields, screenshot, anki) {
+        if (!this._containsMarker(fields, 'screenshot')) { return; }
+
+        const now = new Date(Date.now());
+        const filename = `yomichan_browser_screenshot_${definition.reading}_${this._dateToString(now)}.${screenshot.format}`;
+        const data = screenshot.dataUrl.replace(/^data:[\w\W]*?,/, '');
+
+        try {
+            await anki.storeMediaFile(filename, data);
+        } catch (e) {
+            return;
+        }
+
+        definition.screenshotFileName = filename;
+    }
+
+    _createInjectedAudioFileName(definition) {
+        const {reading, expression} = definition;
+        if (!reading && !expression) { return null; }
+
+        let filename = 'yomichan';
+        if (reading) { filename += `_${reading}`; }
+        if (expression) { filename += `_${expression}`; }
+        filename += '.mp3';
+        return filename;
+    }
+
+    _dateToString(date) {
+        const year = date.getUTCFullYear();
+        const month = date.getUTCMonth().toString().padStart(2, '0');
+        const day = date.getUTCDate().toString().padStart(2, '0');
+        const hours = date.getUTCHours().toString().padStart(2, '0');
+        const minutes = date.getUTCMinutes().toString().padStart(2, '0');
+        const seconds = date.getUTCSeconds().toString().padStart(2, '0');
+        return `${year}-${month}-${day}-${hours}-${minutes}-${seconds}`;
+    }
+
+    _containsMarker(fields, marker) {
+        marker = `{${marker}}`;
+        for (const fieldValue of Object.values(fields)) {
+            if (fieldValue.includes(marker)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     static stringReplaceAsync(str, regex, replacer) {
         let match;
         let index = 0;
diff --git a/ext/bg/js/audio-uri-builder.js b/ext/bg/js/audio-uri-builder.js
index 499c3441..158006bb 100644
--- a/ext/bg/js/audio-uri-builder.js
+++ b/ext/bg/js/audio-uri-builder.js
@@ -17,7 +17,7 @@
  */
 
 /* global
- * jpIsStringEntirelyKana
+ * jp
  */
 
 class AudioUriBuilder {
@@ -66,7 +66,7 @@ class AudioUriBuilder {
         let kana = definition.reading;
         let kanji = definition.expression;
 
-        if (!kana && jpIsStringEntirelyKana(kanji)) {
+        if (!kana && jp.isStringEntirelyKana(kanji)) {
             kana = kanji;
             kanji = null;
         }
diff --git a/ext/bg/js/backend.js b/ext/bg/js/backend.js
index 978c5a4a..1fa7ede1 100644
--- a/ext/bg/js/backend.js
+++ b/ext/bg/js/backend.js
@@ -24,6 +24,8 @@
  * AudioUriBuilder
  * BackendApiForwarder
  * ClipboardMonitor
+ * Database
+ * DictionaryImporter
  * JsonSchema
  * Mecab
  * Translator
@@ -32,9 +34,7 @@
  * dictEnabledSet
  * dictTermsSort
  * handlebarsRenderDynamic
- * jpConvertReading
- * jpDistributeFuriganaInflected
- * jpKatakanaToHiragana
+ * jp
  * optionsLoad
  * optionsSave
  * profileConditionsDescriptor
@@ -45,16 +45,22 @@
 
 class Backend {
     constructor() {
-        this.translator = new Translator();
+        this.database = new Database();
+        this.dictionaryImporter = new DictionaryImporter();
+        this.translator = new Translator(this.database);
         this.anki = new AnkiNull();
         this.mecab = new Mecab();
         this.clipboardMonitor = new ClipboardMonitor({getClipboard: this._onApiClipboardGet.bind(this)});
-        this.ankiNoteBuilder = new AnkiNoteBuilder({renderTemplate: this._renderTemplate.bind(this)});
         this.options = null;
         this.optionsSchema = null;
         this.defaultAnkiFieldTemplates = null;
         this.audioSystem = new AudioSystem({getAudioUri: this._getAudioUri.bind(this)});
         this.audioUriBuilder = new AudioUriBuilder();
+        this.ankiNoteBuilder = new AnkiNoteBuilder({
+            audioSystem: this.audioSystem,
+            renderTemplate: this._renderTemplate.bind(this)
+        });
+
         this.optionsContext = {
             depth: 0,
             url: window.location.href
@@ -109,6 +115,7 @@ class Backend {
     }
 
     async prepare() {
+        await this.database.prepare();
         await this.translator.prepare();
 
         this.optionsSchema = await requestJson(chrome.runtime.getURL('/bg/data/options-schema.json'), 'GET');
@@ -298,6 +305,10 @@ class Backend {
         return true;
     }
 
+    async importDictionary(archiveSource, onProgress, details) {
+        return await this.dictionaryImporter.import(this.database, archiveSource, onProgress, details);
+    }
+
     // Message handlers
 
     _onApiYomichanCoreReady(_params, sender) {
@@ -402,13 +413,13 @@ class Backend {
                 dictTermsSort(definitions);
                 const {expression, reading} = definitions[0];
                 const source = text.substring(0, sourceLength);
-                for (const {text: text2, furigana} of jpDistributeFuriganaInflected(expression, reading, source)) {
-                    const reading2 = jpConvertReading(text2, furigana, options.parsing.readingMode);
+                for (const {text: text2, furigana} of jp.distributeFuriganaInflected(expression, reading, source)) {
+                    const reading2 = jp.convertReading(text2, furigana, options.parsing.readingMode);
                     term.push({text: text2, reading: reading2});
                 }
                 text = text.substring(source.length);
             } else {
-                const reading = jpConvertReading(text[0], null, options.parsing.readingMode);
+                const reading = jp.convertReading(text[0], null, options.parsing.readingMode);
                 term.push({text: text[0], reading});
                 text = text.substring(1);
             }
@@ -427,16 +438,16 @@ class Backend {
                 for (const {expression, reading, source} of parsedLine) {
                     const term = [];
                     if (expression !== null && reading !== null) {
-                        for (const {text: text2, furigana} of jpDistributeFuriganaInflected(
+                        for (const {text: text2, furigana} of jp.distributeFuriganaInflected(
                             expression,
-                            jpKatakanaToHiragana(reading),
+                            jp.convertKatakanaToHiragana(reading),
                             source
                         )) {
-                            const reading2 = jpConvertReading(text2, furigana, options.parsing.readingMode);
+                            const reading2 = jp.convertReading(text2, furigana, options.parsing.readingMode);
                             term.push({text: text2, reading: reading2});
                         }
                     } else {
-                        const reading2 = jpConvertReading(source, null, options.parsing.readingMode);
+                        const reading2 = jp.convertReading(source, null, options.parsing.readingMode);
                         term.push({text: source, reading: reading2});
                     }
                     result.push(term);
@@ -448,12 +459,12 @@ class Backend {
         return results;
     }
 
-    async _onApiDefinitionAdd({definition, mode, context, optionsContext}) {
+    async _onApiDefinitionAdd({definition, mode, context, details, optionsContext}) {
         const options = this.getOptions(optionsContext);
         const templates = this.defaultAnkiFieldTemplates;
 
         if (mode !== 'kanji') {
-            await this._audioInject(
+            await this.ankiNoteBuilder.injectAudio(
                 definition,
                 options.anki.terms.fields,
                 options.audio.sources,
@@ -461,19 +472,20 @@ class Backend {
             );
         }
 
-        if (context && context.screenshot) {
-            await this._injectScreenshot(
+        if (details && details.screenshot) {
+            await this.ankiNoteBuilder.injectScreenshot(
                 definition,
                 options.anki.terms.fields,
-                context.screenshot
+                details.screenshot,
+                this.anki
             );
         }
 
-        const note = await this.ankiNoteBuilder.createNote(definition, mode, options, templates);
+        const note = await this.ankiNoteBuilder.createNote(definition, mode, context, options, templates);
         return this.anki.addNote(note);
     }
 
-    async _onApiDefinitionsAddable({definitions, modes, optionsContext}) {
+    async _onApiDefinitionsAddable({definitions, modes, context, optionsContext}) {
         const options = this.getOptions(optionsContext);
         const templates = this.defaultAnkiFieldTemplates;
         const states = [];
@@ -482,7 +494,7 @@ class Backend {
             const notes = [];
             for (const definition of definitions) {
                 for (const mode of modes) {
-                    const note = await this.ankiNoteBuilder.createNote(definition, mode, options, templates);
+                    const note = await this.ankiNoteBuilder.createNote(definition, mode, context, options, templates);
                     notes.push(note);
                 }
             }
@@ -793,86 +805,10 @@ class Backend {
         return await this.audioUriBuilder.getUri(definition, source, options);
     }
 
-    async _audioInject(definition, fields, sources, optionsContext) {
-        let usesAudio = false;
-        for (const fieldValue of Object.values(fields)) {
-            if (fieldValue.includes('{audio}')) {
-                usesAudio = true;
-                break;
-            }
-        }
-
-        if (!usesAudio) {
-            return true;
-        }
-
-        try {
-            const expressions = definition.expressions;
-            const audioSourceDefinition = Array.isArray(expressions) ? expressions[0] : definition;
-
-            const {uri} = await this.audioSystem.getDefinitionAudio(audioSourceDefinition, sources, {tts: false, optionsContext});
-            const filename = this._createInjectedAudioFileName(audioSourceDefinition);
-            if (filename !== null) {
-                definition.audio = {url: uri, filename};
-            }
-
-            return true;
-        } catch (e) {
-            return false;
-        }
-    }
-
-    async _injectScreenshot(definition, fields, screenshot) {
-        let usesScreenshot = false;
-        for (const fieldValue of Object.values(fields)) {
-            if (fieldValue.includes('{screenshot}')) {
-                usesScreenshot = true;
-                break;
-            }
-        }
-
-        if (!usesScreenshot) {
-            return;
-        }
-
-        const dateToString = (date) => {
-            const year = date.getUTCFullYear();
-            const month = date.getUTCMonth().toString().padStart(2, '0');
-            const day = date.getUTCDate().toString().padStart(2, '0');
-            const hours = date.getUTCHours().toString().padStart(2, '0');
-            const minutes = date.getUTCMinutes().toString().padStart(2, '0');
-            const seconds = date.getUTCSeconds().toString().padStart(2, '0');
-            return `${year}-${month}-${day}-${hours}-${minutes}-${seconds}`;
-        };
-
-        const now = new Date(Date.now());
-        const filename = `yomichan_browser_screenshot_${definition.reading}_${dateToString(now)}.${screenshot.format}`;
-        const data = screenshot.dataUrl.replace(/^data:[\w\W]*?,/, '');
-
-        try {
-            await this.anki.storeMediaFile(filename, data);
-        } catch (e) {
-            return;
-        }
-
-        definition.screenshotFileName = filename;
-    }
-
     async _renderTemplate(template, data) {
         return handlebarsRenderDynamic(template, data);
     }
 
-    _createInjectedAudioFileName(definition) {
-        const {reading, expression} = definition;
-        if (!reading && !expression) { return null; }
-
-        let filename = 'yomichan';
-        if (reading) { filename += `_${reading}`; }
-        if (expression) { filename += `_${expression}`; }
-        filename += '.mp3';
-        return filename;
-    }
-
     static _getTabUrl(tab) {
         return new Promise((resolve) => {
             chrome.tabs.sendMessage(tab.id, {action: 'getUrl'}, {frameId: 0}, (response) => {
diff --git a/ext/bg/js/clipboard-monitor.js b/ext/bg/js/clipboard-monitor.js
index 9a881f57..c67525fc 100644
--- a/ext/bg/js/clipboard-monitor.js
+++ b/ext/bg/js/clipboard-monitor.js
@@ -17,7 +17,7 @@
  */
 
 /* global
- * jpIsStringPartiallyJapanese
+ * jp
  */
 
 class ClipboardMonitor extends EventDispatcher {
@@ -54,7 +54,7 @@ class ClipboardMonitor extends EventDispatcher {
                 text !== this._previousText
             ) {
                 this._previousText = text;
-                if (jpIsStringPartiallyJapanese(text)) {
+                if (jp.isStringPartiallyJapanese(text)) {
                     this.trigger('change', {text});
                 }
             }
diff --git a/ext/bg/js/database.js b/ext/bg/js/database.js
index 08a2a39f..4a677fea 100644
--- a/ext/bg/js/database.js
+++ b/ext/bg/js/database.js
@@ -99,7 +99,7 @@ class Database {
             });
             return true;
         } catch (e) {
-            console.error(e);
+            logError(e);
             return false;
         }
     }
@@ -110,6 +110,10 @@ class Database {
         this.db = null;
     }
 
+    isPrepared() {
+        return this.db !== null;
+    }
+
     async purge() {
         this._validate();
 
@@ -322,177 +326,44 @@ class Database {
         return result;
     }
 
-    async importDictionary(archiveSource, onProgress, details) {
+    async dictionaryExists(title) {
         this._validate();
-        const db = this.db;
-        const hasOnProgress = (typeof onProgress === 'function');
-
-        // Read archive
-        const archive = await JSZip.loadAsync(archiveSource);
-
-        // Read and validate index
-        const indexFileName = 'index.json';
-        const indexFile = archive.files[indexFileName];
-        if (!indexFile) {
-            throw new Error('No dictionary index found in archive');
-        }
-
-        const index = JSON.parse(await indexFile.async('string'));
-
-        const indexSchema = await this._getSchema('/bg/data/dictionary-index-schema.json');
-        Database._validateJsonSchema(index, indexSchema, indexFileName);
-
-        const dictionaryTitle = index.title;
-        const version = index.format || index.version;
-
-        if (!dictionaryTitle || !index.revision) {
-            throw new Error('Unrecognized dictionary format');
-        }
-
-        // Verify database is not already imported
-        if (await this._dictionaryExists(dictionaryTitle)) {
-            throw new Error('Dictionary is already imported');
-        }
-
-        // Data format converters
-        const convertTermBankEntry = (entry) => {
-            if (version === 1) {
-                const [expression, reading, definitionTags, rules, score, ...glossary] = entry;
-                return {expression, reading, definitionTags, rules, score, glossary};
-            } else {
-                const [expression, reading, definitionTags, rules, score, glossary, sequence, termTags] = entry;
-                return {expression, reading, definitionTags, rules, score, glossary, sequence, termTags};
-            }
-        };
-
-        const convertTermMetaBankEntry = (entry) => {
-            const [expression, mode, data] = entry;
-            return {expression, mode, data};
-        };
-
-        const convertKanjiBankEntry = (entry) => {
-            if (version === 1) {
-                const [character, onyomi, kunyomi, tags, ...meanings] = entry;
-                return {character, onyomi, kunyomi, tags, meanings};
-            } else {
-                const [character, onyomi, kunyomi, tags, meanings, stats] = entry;
-                return {character, onyomi, kunyomi, tags, meanings, stats};
-            }
-        };
-
-        const convertKanjiMetaBankEntry = (entry) => {
-            const [character, mode, data] = entry;
-            return {character, mode, data};
-        };
-
-        const convertTagBankEntry = (entry) => {
-            const [name, category, order, notes, score] = entry;
-            return {name, category, order, notes, score};
-        };
+        const transaction = this.db.transaction(['dictionaries'], 'readonly');
+        const index = transaction.objectStore('dictionaries').index('title');
+        const query = IDBKeyRange.only(title);
+        const count = await Database._getCount(index, query);
+        return count > 0;
+    }
 
-        // Archive file reading
-        const readFileSequence = async (fileNameFormat, convertEntry, schema) => {
-            const results = [];
-            for (let i = 1; true; ++i) {
-                const fileName = fileNameFormat.replace(/\?/, `${i}`);
-                const file = archive.files[fileName];
-                if (!file) { break; }
-
-                const entries = JSON.parse(await file.async('string'));
-                Database._validateJsonSchema(entries, schema, fileName);
-
-                for (let entry of entries) {
-                    entry = convertEntry(entry);
-                    entry.dictionary = dictionaryTitle;
-                    results.push(entry);
-                }
-            }
-            return results;
-        };
+    bulkAdd(objectStoreName, items, start, count) {
+        return new Promise((resolve, reject) => {
+            const transaction = this.db.transaction([objectStoreName], 'readwrite');
+            const objectStore = transaction.objectStore(objectStoreName);
 
-        // Load schemas
-        const dataBankSchemaPaths = this.constructor._getDataBankSchemaPaths(version);
-        const dataBankSchemas = await Promise.all(dataBankSchemaPaths.map((path) => this._getSchema(path)));
-
-        // Load data
-        const termList      = await readFileSequence('term_bank_?.json',       convertTermBankEntry,      dataBankSchemas[0]);
-        const termMetaList  = await readFileSequence('term_meta_bank_?.json',  convertTermMetaBankEntry,  dataBankSchemas[1]);
-        const kanjiList     = await readFileSequence('kanji_bank_?.json',      convertKanjiBankEntry,     dataBankSchemas[2]);
-        const kanjiMetaList = await readFileSequence('kanji_meta_bank_?.json', convertKanjiMetaBankEntry, dataBankSchemas[3]);
-        const tagList       = await readFileSequence('tag_bank_?.json',        convertTagBankEntry,       dataBankSchemas[4]);
-
-        // Old tags
-        const indexTagMeta = index.tagMeta;
-        if (typeof indexTagMeta === 'object' && indexTagMeta !== null) {
-            for (const name of Object.keys(indexTagMeta)) {
-                const {category, order, notes, score} = indexTagMeta[name];
-                tagList.push({name, category, order, notes, score});
+            if (start + count > items.length) {
+                count = items.length - start;
             }
-        }
 
-        // Prefix wildcard support
-        const prefixWildcardsSupported = !!details.prefixWildcardsSupported;
-        if (prefixWildcardsSupported) {
-            for (const entry of termList) {
-                entry.expressionReverse = stringReverse(entry.expression);
-                entry.readingReverse = stringReverse(entry.reading);
+            if (count <= 0) {
+                resolve();
+                return;
             }
-        }
-
-        // Add dictionary
-        const summary = {
-            title: dictionaryTitle,
-            revision: index.revision,
-            sequenced: index.sequenced,
-            version,
-            prefixWildcardsSupported
-        };
-
-        {
-            const transaction = db.transaction(['dictionaries'], 'readwrite');
-            const objectStore = transaction.objectStore('dictionaries');
-            await Database._bulkAdd(objectStore, [summary], 0, 1);
-        }
-
-        // Add data
-        const errors = [];
-        const total = (
-            termList.length +
-            termMetaList.length +
-            kanjiList.length +
-            kanjiMetaList.length +
-            tagList.length
-        );
-        let loadedCount = 0;
-        const maxTransactionLength = 1000;
-
-        const bulkAdd = async (objectStoreName, entries) => {
-            const ii = entries.length;
-            for (let i = 0; i < ii; i += maxTransactionLength) {
-                const count = Math.min(maxTransactionLength, ii - i);
 
-                try {
-                    const transaction = db.transaction([objectStoreName], 'readwrite');
-                    const objectStore = transaction.objectStore(objectStoreName);
-                    await Database._bulkAdd(objectStore, entries, i, count);
-                } catch (e) {
-                    errors.push(e);
+            const end = start + count;
+            let completedCount = 0;
+            const onError = (e) => reject(e);
+            const onSuccess = () => {
+                if (++completedCount >= count) {
+                    resolve();
                 }
+            };
 
-                loadedCount += count;
-                if (hasOnProgress) {
-                    onProgress(total, loadedCount);
-                }
+            for (let i = start; i < end; ++i) {
+                const request = objectStore.add(items[i]);
+                request.onerror = onError;
+                request.onsuccess = onSuccess;
             }
-        };
-
-        await bulkAdd('terms', termList);
-        await bulkAdd('termMeta', termMetaList);
-        await bulkAdd('kanji', kanjiList);
-        await bulkAdd('kanjiMeta', kanjiMetaList);
-        await bulkAdd('tagMeta', tagList);
-
-        return {result: summary, errors};
+        });
     }
 
     // Private
@@ -503,80 +374,6 @@ class Database {
         }
     }
 
-    async _getSchema(fileName) {
-        let schemaPromise = this._schemas.get(fileName);
-        if (typeof schemaPromise !== 'undefined') {
-            return schemaPromise;
-        }
-
-        schemaPromise = requestJson(chrome.runtime.getURL(fileName), 'GET');
-        this._schemas.set(fileName, schemaPromise);
-        return schemaPromise;
-    }
-
-    static _validateJsonSchema(value, schema, fileName) {
-        try {
-            JsonSchema.validate(value, schema);
-        } catch (e) {
-            throw Database._formatSchemaError(e, fileName);
-        }
-    }
-
-    static _formatSchemaError(e, fileName) {
-        const valuePathString = Database._getSchemaErrorPathString(e.info.valuePath, 'dictionary');
-        const schemaPathString = Database._getSchemaErrorPathString(e.info.schemaPath, 'schema');
-
-        const e2 = new Error(`Dictionary has invalid data in '${fileName}' for value '${valuePathString}', validated against '${schemaPathString}': ${e.message}`);
-        e2.data = e;
-
-        return e2;
-    }
-
-    static _getSchemaErrorPathString(infoList, base='') {
-        let result = base;
-        for (const [part] of infoList) {
-            switch (typeof part) {
-                case 'string':
-                    if (result.length > 0) {
-                        result += '.';
-                    }
-                    result += part;
-                    break;
-                case 'number':
-                    result += `[${part}]`;
-                    break;
-            }
-        }
-        return result;
-    }
-
-    static _getDataBankSchemaPaths(version) {
-        const termBank = (
-            version === 1 ?
-            '/bg/data/dictionary-term-bank-v1-schema.json' :
-            '/bg/data/dictionary-term-bank-v3-schema.json'
-        );
-        const termMetaBank = '/bg/data/dictionary-term-meta-bank-v3-schema.json';
-        const kanjiBank = (
-            version === 1 ?
-            '/bg/data/dictionary-kanji-bank-v1-schema.json' :
-            '/bg/data/dictionary-kanji-bank-v3-schema.json'
-        );
-        const kanjiMetaBank = '/bg/data/dictionary-kanji-meta-bank-v3-schema.json';
-        const tagBank = '/bg/data/dictionary-tag-bank-v3-schema.json';
-
-        return [termBank, termMetaBank, kanjiBank, kanjiMetaBank, tagBank];
-    }
-
-    async _dictionaryExists(title) {
-        const db = this.db;
-        const dbCountTransaction = db.transaction(['dictionaries'], 'readonly');
-        const dbIndex = dbCountTransaction.objectStore('dictionaries').index('title');
-        const only = IDBKeyRange.only(title);
-        const count = await Database._getCount(dbIndex, only);
-        return count > 0;
-    }
-
     async _findGenericBulk(tableName, indexName, indexValueList, dictionaries, createResult) {
         this._validate();
 
@@ -760,34 +557,6 @@ class Database {
         });
     }
 
-    static _bulkAdd(objectStore, items, start, count) {
-        return new Promise((resolve, reject) => {
-            if (start + count > items.length) {
-                count = items.length - start;
-            }
-
-            if (count <= 0) {
-                resolve();
-                return;
-            }
-
-            const end = start + count;
-            let completedCount = 0;
-            const onError = (e) => reject(e);
-            const onSuccess = () => {
-                if (++completedCount >= count) {
-                    resolve();
-                }
-            };
-
-            for (let i = start; i < end; ++i) {
-                const request = objectStore.add(items[i]);
-                request.onerror = onError;
-                request.onsuccess = onSuccess;
-            }
-        });
-    }
-
     static _open(name, version, onUpgradeNeeded) {
         return new Promise((resolve, reject) => {
             const request = window.indexedDB.open(name, version * 10);
diff --git a/ext/bg/js/dictionary-importer.js b/ext/bg/js/dictionary-importer.js
new file mode 100644
index 00000000..254fde4f
--- /dev/null
+++ b/ext/bg/js/dictionary-importer.js
@@ -0,0 +1,279 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* global
+ * JSZip
+ * JsonSchema
+ * requestJson
+ */
+
+class DictionaryImporter {
+    constructor() {
+        this._schemas = new Map();
+    }
+
+    async import(database, archiveSource, onProgress, details) {
+        if (!database) {
+            throw new Error('Invalid database');
+        }
+        if (!database.isPrepared()) {
+            throw new Error('Database is not ready');
+        }
+
+        const hasOnProgress = (typeof onProgress === 'function');
+
+        // Read archive
+        const archive = await JSZip.loadAsync(archiveSource);
+
+        // Read and validate index
+        const indexFileName = 'index.json';
+        const indexFile = archive.files[indexFileName];
+        if (!indexFile) {
+            throw new Error('No dictionary index found in archive');
+        }
+
+        const index = JSON.parse(await indexFile.async('string'));
+
+        const indexSchema = await this._getSchema('/bg/data/dictionary-index-schema.json');
+        this._validateJsonSchema(index, indexSchema, indexFileName);
+
+        const dictionaryTitle = index.title;
+        const version = index.format || index.version;
+
+        if (!dictionaryTitle || !index.revision) {
+            throw new Error('Unrecognized dictionary format');
+        }
+
+        // Verify database is not already imported
+        if (await database.dictionaryExists(dictionaryTitle)) {
+            throw new Error('Dictionary is already imported');
+        }
+
+        // Data format converters
+        const convertTermBankEntry = (entry) => {
+            if (version === 1) {
+                const [expression, reading, definitionTags, rules, score, ...glossary] = entry;
+                return {expression, reading, definitionTags, rules, score, glossary};
+            } else {
+                const [expression, reading, definitionTags, rules, score, glossary, sequence, termTags] = entry;
+                return {expression, reading, definitionTags, rules, score, glossary, sequence, termTags};
+            }
+        };
+
+        const convertTermMetaBankEntry = (entry) => {
+            const [expression, mode, data] = entry;
+            return {expression, mode, data};
+        };
+
+        const convertKanjiBankEntry = (entry) => {
+            if (version === 1) {
+                const [character, onyomi, kunyomi, tags, ...meanings] = entry;
+                return {character, onyomi, kunyomi, tags, meanings};
+            } else {
+                const [character, onyomi, kunyomi, tags, meanings, stats] = entry;
+                return {character, onyomi, kunyomi, tags, meanings, stats};
+            }
+        };
+
+        const convertKanjiMetaBankEntry = (entry) => {
+            const [character, mode, data] = entry;
+            return {character, mode, data};
+        };
+
+        const convertTagBankEntry = (entry) => {
+            const [name, category, order, notes, score] = entry;
+            return {name, category, order, notes, score};
+        };
+
+        // Archive file reading
+        const readFileSequence = async (fileNameFormat, convertEntry, schema) => {
+            const results = [];
+            for (let i = 1; true; ++i) {
+                const fileName = fileNameFormat.replace(/\?/, `${i}`);
+                const file = archive.files[fileName];
+                if (!file) { break; }
+
+                const entries = JSON.parse(await file.async('string'));
+                this._validateJsonSchema(entries, schema, fileName);
+
+                for (let entry of entries) {
+                    entry = convertEntry(entry);
+                    entry.dictionary = dictionaryTitle;
+                    results.push(entry);
+                }
+            }
+            return results;
+        };
+
+        // Load schemas
+        const dataBankSchemaPaths = this._getDataBankSchemaPaths(version);
+        const dataBankSchemas = await Promise.all(dataBankSchemaPaths.map((path) => this._getSchema(path)));
+
+        // Load data
+        const termList      = await readFileSequence('term_bank_?.json',       convertTermBankEntry,      dataBankSchemas[0]);
+        const termMetaList  = await readFileSequence('term_meta_bank_?.json',  convertTermMetaBankEntry,  dataBankSchemas[1]);
+        const kanjiList     = await readFileSequence('kanji_bank_?.json',      convertKanjiBankEntry,     dataBankSchemas[2]);
+        const kanjiMetaList = await readFileSequence('kanji_meta_bank_?.json', convertKanjiMetaBankEntry, dataBankSchemas[3]);
+        const tagList       = await readFileSequence('tag_bank_?.json',        convertTagBankEntry,       dataBankSchemas[4]);
+
+        // Old tags
+        const indexTagMeta = index.tagMeta;
+        if (typeof indexTagMeta === 'object' && indexTagMeta !== null) {
+            for (const name of Object.keys(indexTagMeta)) {
+                const {category, order, notes, score} = indexTagMeta[name];
+                tagList.push({name, category, order, notes, score});
+            }
+        }
+
+        // Prefix wildcard support
+        const prefixWildcardsSupported = !!details.prefixWildcardsSupported;
+        if (prefixWildcardsSupported) {
+            for (const entry of termList) {
+                entry.expressionReverse = stringReverse(entry.expression);
+                entry.readingReverse = stringReverse(entry.reading);
+            }
+        }
+
+        // Add dictionary
+        const summary = this._createSummary(dictionaryTitle, version, index, {prefixWildcardsSupported});
+
+        database.bulkAdd('dictionaries', [summary], 0, 1);
+
+        // Add data
+        const errors = [];
+        const total = (
+            termList.length +
+            termMetaList.length +
+            kanjiList.length +
+            kanjiMetaList.length +
+            tagList.length
+        );
+        let loadedCount = 0;
+        const maxTransactionLength = 1000;
+
+        const bulkAdd = async (objectStoreName, entries) => {
+            const ii = entries.length;
+            for (let i = 0; i < ii; i += maxTransactionLength) {
+                const count = Math.min(maxTransactionLength, ii - i);
+
+                try {
+                    await database.bulkAdd(objectStoreName, entries, i, count);
+                } catch (e) {
+                    errors.push(errorToJson(e));
+                }
+
+                loadedCount += count;
+                if (hasOnProgress) {
+                    onProgress(total, loadedCount);
+                }
+            }
+        };
+
+        await bulkAdd('terms', termList);
+        await bulkAdd('termMeta', termMetaList);
+        await bulkAdd('kanji', kanjiList);
+        await bulkAdd('kanjiMeta', kanjiMetaList);
+        await bulkAdd('tagMeta', tagList);
+
+        return {result: summary, errors};
+    }
+
+    _createSummary(dictionaryTitle, version, index, details) {
+        const summary = {
+            title: dictionaryTitle,
+            revision: index.revision,
+            sequenced: index.sequenced,
+            version
+        };
+
+        const {author, url, description, attribution} = index;
+        if (typeof author === 'string') { summary.author = author; }
+        if (typeof url === 'string') { summary.url = url; }
+        if (typeof description === 'string') { summary.description = description; }
+        if (typeof attribution === 'string') { summary.attribution = attribution; }
+
+        Object.assign(summary, details);
+
+        return summary;
+    }
+
+    async _getSchema(fileName) {
+        let schemaPromise = this._schemas.get(fileName);
+        if (typeof schemaPromise !== 'undefined') {
+            return schemaPromise;
+        }
+
+        schemaPromise = requestJson(chrome.runtime.getURL(fileName), 'GET');
+        this._schemas.set(fileName, schemaPromise);
+        return schemaPromise;
+    }
+
+    _validateJsonSchema(value, schema, fileName) {
+        try {
+            JsonSchema.validate(value, schema);
+        } catch (e) {
+            throw this._formatSchemaError(e, fileName);
+        }
+    }
+
+    _formatSchemaError(e, fileName) {
+        const valuePathString = this._getSchemaErrorPathString(e.info.valuePath, 'dictionary');
+        const schemaPathString = this._getSchemaErrorPathString(e.info.schemaPath, 'schema');
+
+        const e2 = new Error(`Dictionary has invalid data in '${fileName}' for value '${valuePathString}', validated against '${schemaPathString}': ${e.message}`);
+        e2.data = e;
+
+        return e2;
+    }
+
+    _getSchemaErrorPathString(infoList, base='') {
+        let result = base;
+        for (const [part] of infoList) {
+            switch (typeof part) {
+                case 'string':
+                    if (result.length > 0) {
+                        result += '.';
+                    }
+                    result += part;
+                    break;
+                case 'number':
+                    result += `[${part}]`;
+                    break;
+            }
+        }
+        return result;
+    }
+
+    _getDataBankSchemaPaths(version) {
+        const termBank = (
+            version === 1 ?
+            '/bg/data/dictionary-term-bank-v1-schema.json' :
+            '/bg/data/dictionary-term-bank-v3-schema.json'
+        );
+        const termMetaBank = '/bg/data/dictionary-term-meta-bank-v3-schema.json';
+        const kanjiBank = (
+            version === 1 ?
+            '/bg/data/dictionary-kanji-bank-v1-schema.json' :
+            '/bg/data/dictionary-kanji-bank-v3-schema.json'
+        );
+        const kanjiMetaBank = '/bg/data/dictionary-kanji-meta-bank-v3-schema.json';
+        const tagBank = '/bg/data/dictionary-tag-bank-v3-schema.json';
+
+        return [termBank, termMetaBank, kanjiBank, kanjiMetaBank, tagBank];
+    }
+}
diff --git a/ext/bg/js/dictionary.js b/ext/bg/js/dictionary.js
index 3dd1d0c1..74bd5a64 100644
--- a/ext/bg/js/dictionary.js
+++ b/ext/bg/js/dictionary.js
@@ -137,30 +137,6 @@ function dictTermsGroup(definitions, dictionaries) {
     return dictTermsSort(results);
 }
 
-function dictAreSetsEqual(set1, set2) {
-    if (set1.size !== set2.size) {
-        return false;
-    }
-
-    for (const value of set1) {
-        if (!set2.has(value)) {
-            return false;
-        }
-    }
-
-    return true;
-}
-
-function dictGetSetIntersection(set1, set2) {
-    const result = [];
-    for (const value of set1) {
-        if (set2.has(value)) {
-            result.push(value);
-        }
-    }
-    return result;
-}
-
 function dictTermsMergeBySequence(definitions, mainDictionary) {
     const sequencedDefinitions = new Map();
     const nonSequencedDefinitions = [];
@@ -281,11 +257,11 @@ function dictTermsMergeByGloss(result, definitions, appendTo=null, mergedIndices
         const only = [];
         const expressionSet = definition.expression;
         const readingSet = definition.reading;
-        if (!dictAreSetsEqual(expressionSet, resultExpressionSet)) {
-            only.push(...dictGetSetIntersection(expressionSet, resultExpressionSet));
+        if (!areSetsEqual(expressionSet, resultExpressionSet)) {
+            only.push(...getSetIntersection(expressionSet, resultExpressionSet));
         }
-        if (!dictAreSetsEqual(readingSet, resultReadingSet)) {
-            only.push(...dictGetSetIntersection(readingSet, resultReadingSet));
+        if (!areSetsEqual(readingSet, resultReadingSet)) {
+            only.push(...getSetIntersection(readingSet, resultReadingSet));
         }
         definition.only = only;
     }
diff --git a/ext/bg/js/handlebars.js b/ext/bg/js/handlebars.js
index e3ce6bd0..5fda5baa 100644
--- a/ext/bg/js/handlebars.js
+++ b/ext/bg/js/handlebars.js
@@ -18,8 +18,7 @@
 
 /* global
  * Handlebars
- * jpDistributeFurigana
- * jpIsCodePointKanji
+ * jp
  */
 
 function handlebarsEscape(text) {
@@ -33,7 +32,7 @@ function handlebarsDumpObject(options) {
 
 function handlebarsFurigana(options) {
     const definition = options.fn(this);
-    const segs = jpDistributeFurigana(definition.expression, definition.reading);
+    const segs = jp.distributeFurigana(definition.expression, definition.reading);
 
     let result = '';
     for (const seg of segs) {
@@ -49,7 +48,7 @@ function handlebarsFurigana(options) {
 
 function handlebarsFuriganaPlain(options) {
     const definition = options.fn(this);
-    const segs = jpDistributeFurigana(definition.expression, definition.reading);
+    const segs = jp.distributeFurigana(definition.expression, definition.reading);
 
     let result = '';
     for (const seg of segs) {
@@ -66,7 +65,7 @@ function handlebarsFuriganaPlain(options) {
 function handlebarsKanjiLinks(options) {
     let result = '';
     for (const c of options.fn(this)) {
-        if (jpIsCodePointKanji(c.codePointAt(0))) {
+        if (jp.isCodePointKanji(c.codePointAt(0))) {
             result += `<a href="#" class="kanji-link">${c}</a>`;
         } else {
             result += c;
diff --git a/ext/bg/js/japanese.js b/ext/bg/js/japanese.js
index 3b37754d..2a2b39fd 100644
--- a/ext/bg/js/japanese.js
+++ b/ext/bg/js/japanese.js
@@ -17,442 +17,373 @@
  */
 
 /* global
+ * jp
  * wanakana
  */
 
-const JP_HALFWIDTH_KATAKANA_MAPPING = new Map([
-    ['ｦ', 'ヲヺ-'],
-    ['ｧ', 'ァ--'],
-    ['ｨ', 'ィ--'],
-    ['ｩ', 'ゥ--'],
-    ['ｪ', 'ェ--'],
-    ['ｫ', 'ォ--'],
-    ['ｬ', 'ャ--'],
-    ['ｭ', 'ュ--'],
-    ['ｮ', 'ョ--'],
-    ['ｯ', 'ッ--'],
-    ['ｰ', 'ー--'],
-    ['ｱ', 'ア--'],
-    ['ｲ', 'イ--'],
-    ['ｳ', 'ウヴ-'],
-    ['ｴ', 'エ--'],
-    ['ｵ', 'オ--'],
-    ['ｶ', 'カガ-'],
-    ['ｷ', 'キギ-'],
-    ['ｸ', 'クグ-'],
-    ['ｹ', 'ケゲ-'],
-    ['ｺ', 'コゴ-'],
-    ['ｻ', 'サザ-'],
-    ['ｼ', 'シジ-'],
-    ['ｽ', 'スズ-'],
-    ['ｾ', 'セゼ-'],
-    ['ｿ', 'ソゾ-'],
-    ['ﾀ', 'タダ-'],
-    ['ﾁ', 'チヂ-'],
-    ['ﾂ', 'ツヅ-'],
-    ['ﾃ', 'テデ-'],
-    ['ﾄ', 'トド-'],
-    ['ﾅ', 'ナ--'],
-    ['ﾆ', 'ニ--'],
-    ['ﾇ', 'ヌ--'],
-    ['ﾈ', 'ネ--'],
-    ['ﾉ', 'ノ--'],
-    ['ﾊ', 'ハバパ'],
-    ['ﾋ', 'ヒビピ'],
-    ['ﾌ', 'フブプ'],
-    ['ﾍ', 'ヘベペ'],
-    ['ﾎ', 'ホボポ'],
-    ['ﾏ', 'マ--'],
-    ['ﾐ', 'ミ--'],
-    ['ﾑ', 'ム--'],
-    ['ﾒ', 'メ--'],
-    ['ﾓ', 'モ--'],
-    ['ﾔ', 'ヤ--'],
-    ['ﾕ', 'ユ--'],
-    ['ﾖ', 'ヨ--'],
-    ['ﾗ', 'ラ--'],
-    ['ﾘ', 'リ--'],
-    ['ﾙ', 'ル--'],
-    ['ﾚ', 'レ--'],
-    ['ﾛ', 'ロ--'],
-    ['ﾜ', 'ワ--'],
-    ['ﾝ', 'ン--']
-]);
-
-const JP_HIRAGANA_RANGE = [0x3040, 0x309f];
-const JP_KATAKANA_RANGE = [0x30a0, 0x30ff];
-const JP_KANA_RANGES = [JP_HIRAGANA_RANGE, JP_KATAKANA_RANGE];
-
-const JP_CJK_COMMON_RANGE = [0x4e00, 0x9fff];
-const JP_CJK_RARE_RANGE = [0x3400, 0x4dbf];
-const JP_CJK_RANGES = [JP_CJK_COMMON_RANGE, JP_CJK_RARE_RANGE];
-
-const JP_ITERATION_MARK_CHAR_CODE = 0x3005;
-
-// Japanese character ranges, roughly ordered in order of expected frequency
-const JP_JAPANESE_RANGES = [
-    JP_HIRAGANA_RANGE,
-    JP_KATAKANA_RANGE,
-
-    JP_CJK_COMMON_RANGE,
-    JP_CJK_RARE_RANGE,
-
-    [0xff66, 0xff9f], // Halfwidth katakana
-
-    [0x30fb, 0x30fc], // Katakana punctuation
-    [0xff61, 0xff65], // Kana punctuation
-    [0x3000, 0x303f], // CJK punctuation
-
-    [0xff10, 0xff19], // Fullwidth numbers
-    [0xff21, 0xff3a], // Fullwidth upper case Latin letters
-    [0xff41, 0xff5a], // Fullwidth lower case Latin letters
-
-    [0xff01, 0xff0f], // Fullwidth punctuation 1
-    [0xff1a, 0xff1f], // Fullwidth punctuation 2
-    [0xff3b, 0xff3f], // Fullwidth punctuation 3
-    [0xff5b, 0xff60], // Fullwidth punctuation 4
-    [0xffe0, 0xffee]  // Currency markers
-];
-
-
-// Helper functions
-
-function _jpIsCodePointInRanges(codePoint, ranges) {
-    for (const [min, max] of ranges) {
-        if (codePoint >= min && codePoint <= max) {
-            return true;
+(() => {
+    const HALFWIDTH_KATAKANA_MAPPING = new Map([
+        ['ｦ', 'ヲヺ-'],
+        ['ｧ', 'ァ--'],
+        ['ｨ', 'ィ--'],
+        ['ｩ', 'ゥ--'],
+        ['ｪ', 'ェ--'],
+        ['ｫ', 'ォ--'],
+        ['ｬ', 'ャ--'],
+        ['ｭ', 'ュ--'],
+        ['ｮ', 'ョ--'],
+        ['ｯ', 'ッ--'],
+        ['ｰ', 'ー--'],
+        ['ｱ', 'ア--'],
+        ['ｲ', 'イ--'],
+        ['ｳ', 'ウヴ-'],
+        ['ｴ', 'エ--'],
+        ['ｵ', 'オ--'],
+        ['ｶ', 'カガ-'],
+        ['ｷ', 'キギ-'],
+        ['ｸ', 'クグ-'],
+        ['ｹ', 'ケゲ-'],
+        ['ｺ', 'コゴ-'],
+        ['ｻ', 'サザ-'],
+        ['ｼ', 'シジ-'],
+        ['ｽ', 'スズ-'],
+        ['ｾ', 'セゼ-'],
+        ['ｿ', 'ソゾ-'],
+        ['ﾀ', 'タダ-'],
+        ['ﾁ', 'チヂ-'],
+        ['ﾂ', 'ツヅ-'],
+        ['ﾃ', 'テデ-'],
+        ['ﾄ', 'トド-'],
+        ['ﾅ', 'ナ--'],
+        ['ﾆ', 'ニ--'],
+        ['ﾇ', 'ヌ--'],
+        ['ﾈ', 'ネ--'],
+        ['ﾉ', 'ノ--'],
+        ['ﾊ', 'ハバパ'],
+        ['ﾋ', 'ヒビピ'],
+        ['ﾌ', 'フブプ'],
+        ['ﾍ', 'ヘベペ'],
+        ['ﾎ', 'ホボポ'],
+        ['ﾏ', 'マ--'],
+        ['ﾐ', 'ミ--'],
+        ['ﾑ', 'ム--'],
+        ['ﾒ', 'メ--'],
+        ['ﾓ', 'モ--'],
+        ['ﾔ', 'ヤ--'],
+        ['ﾕ', 'ユ--'],
+        ['ﾖ', 'ヨ--'],
+        ['ﾗ', 'ラ--'],
+        ['ﾘ', 'リ--'],
+        ['ﾙ', 'ル--'],
+        ['ﾚ', 'レ--'],
+        ['ﾛ', 'ロ--'],
+        ['ﾜ', 'ワ--'],
+        ['ﾝ', 'ン--']
+    ]);
+
+    const ITERATION_MARK_CODE_POINT = 0x3005;
+
+
+    // Existing functions
+
+    const isCodePointKanji = jp.isCodePointKanji;
+    const isStringEntirelyKana = jp.isStringEntirelyKana;
+
+
+    // Conversion functions
+
+    function convertKatakanaToHiragana(text) {
+        let result = '';
+        for (const c of text) {
+            if (wanakana.isKatakana(c)) {
+                result += wanakana.toHiragana(c);
+            } else {
+                result += c;
+            }
         }
-    }
-    return false;
-}
-
-
-// Character code testing functions
 
-function jpIsCodePointKanji(codePoint) {
-    return _jpIsCodePointInRanges(codePoint, JP_CJK_RANGES);
-}
-
-function jpIsCodePointKana(codePoint) {
-    return _jpIsCodePointInRanges(codePoint, JP_KANA_RANGES);
-}
+        return result;
+    }
 
-function jpIsCodePointJapanese(codePoint) {
-    return _jpIsCodePointInRanges(codePoint, JP_JAPANESE_RANGES);
-}
+    function convertHiraganaToKatakana(text) {
+        let result = '';
+        for (const c of text) {
+            if (wanakana.isHiragana(c)) {
+                result += wanakana.toKatakana(c);
+            } else {
+                result += c;
+            }
+        }
 
+        return result;
+    }
 
-// String testing functions
+    function convertToRomaji(text) {
+        return wanakana.toRomaji(text);
+    }
 
-function jpIsStringEntirelyKana(str) {
-    if (str.length === 0) { return false; }
-    for (const c of str) {
-        if (!jpIsCodePointKana(c.codePointAt(0))) {
-            return false;
+    function convertReading(expressionFragment, readingFragment, readingMode) {
+        switch (readingMode) {
+            case 'hiragana':
+                return convertKatakanaToHiragana(readingFragment || '');
+            case 'katakana':
+                return convertHiraganaToKatakana(readingFragment || '');
+            case 'romaji':
+                if (readingFragment) {
+                    return convertToRomaji(readingFragment);
+                } else {
+                    if (isStringEntirelyKana(expressionFragment)) {
+                        return convertToRomaji(expressionFragment);
+                    }
+                }
+                return readingFragment;
+            case 'none':
+                return null;
+            default:
+                return readingFragment;
         }
     }
-    return true;
-}
-
-function jpIsStringPartiallyJapanese(str) {
-    if (str.length === 0) { return false; }
-    for (const c of str) {
-        if (jpIsCodePointJapanese(c.codePointAt(0))) {
-            return true;
+
+    function convertNumericToFullWidth(text) {
+        let result = '';
+        for (const char of text) {
+            let c = char.codePointAt(0);
+            if (c >= 0x30 && c <= 0x39) { // ['0', '9']
+                c += 0xff10 - 0x30; // 0xff10 = '0' full width
+                result += String.fromCodePoint(c);
+            } else {
+                result += char;
+            }
         }
+        return result;
     }
-    return false;
-}
 
+    function convertHalfWidthKanaToFullWidth(text, sourceMap=null) {
+        let result = '';
+
+        // This function is safe to use charCodeAt instead of codePointAt, since all
+        // the relevant characters are represented with a single UTF-16 character code.
+        for (let i = 0, ii = text.length; i < ii; ++i) {
+            const c = text[i];
+            const mapping = HALFWIDTH_KATAKANA_MAPPING.get(c);
+            if (typeof mapping !== 'string') {
+                result += c;
+                continue;
+            }
 
-// Conversion functions
-
-function jpKatakanaToHiragana(text) {
-    let result = '';
-    for (const c of text) {
-        if (wanakana.isKatakana(c)) {
-            result += wanakana.toHiragana(c);
-        } else {
-            result += c;
-        }
-    }
+            let index = 0;
+            switch (text.charCodeAt(i + 1)) {
+                case 0xff9e: // dakuten
+                    index = 1;
+                    break;
+                case 0xff9f: // handakuten
+                    index = 2;
+                    break;
+            }
 
-    return result;
-}
+            let c2 = mapping[index];
+            if (index > 0) {
+                if (c2 === '-') { // invalid
+                    index = 0;
+                    c2 = mapping[0];
+                } else {
+                    ++i;
+                }
+            }
 
-function jpHiraganaToKatakana(text) {
-    let result = '';
-    for (const c of text) {
-        if (wanakana.isHiragana(c)) {
-            result += wanakana.toKatakana(c);
-        } else {
-            result += c;
+            if (sourceMap !== null && index > 0) {
+                sourceMap.combine(result.length, 1);
+            }
+            result += c2;
         }
+
+        return result;
     }
 
-    return result;
-}
-
-function jpToRomaji(text) {
-    return wanakana.toRomaji(text);
-}
-
-function jpConvertReading(expressionFragment, readingFragment, readingMode) {
-    switch (readingMode) {
-        case 'hiragana':
-            return jpKatakanaToHiragana(readingFragment || '');
-        case 'katakana':
-            return jpHiraganaToKatakana(readingFragment || '');
-        case 'romaji':
-            if (readingFragment) {
-                return jpToRomaji(readingFragment);
+    function convertAlphabeticToKana(text, sourceMap=null) {
+        let part = '';
+        let result = '';
+
+        for (const char of text) {
+            // Note: 0x61 is the character code for 'a'
+            let c = char.codePointAt(0);
+            if (c >= 0x41 && c <= 0x5a) { // ['A', 'Z']
+                c += (0x61 - 0x41);
+            } else if (c >= 0x61 && c <= 0x7a) { // ['a', 'z']
+                // NOP; c += (0x61 - 0x61);
+            } else if (c >= 0xff21 && c <= 0xff3a) { // ['A', 'Z'] fullwidth
+                c += (0x61 - 0xff21);
+            } else if (c >= 0xff41 && c <= 0xff5a) { // ['a', 'z'] fullwidth
+                c += (0x61 - 0xff41);
+            } else if (c === 0x2d || c === 0xff0d) { // '-' or fullwidth dash
+                c = 0x2d; // '-'
             } else {
-                if (jpIsStringEntirelyKana(expressionFragment)) {
-                    return jpToRomaji(expressionFragment);
+                if (part.length > 0) {
+                    result += convertAlphabeticPartToKana(part, sourceMap, result.length);
+                    part = '';
                 }
+                result += char;
+                continue;
             }
-            return readingFragment;
-        case 'none':
-            return null;
-        default:
-            return readingFragment;
-    }
-}
-
-function jpDistributeFurigana(expression, reading) {
-    const fallback = [{furigana: reading, text: expression}];
-    if (!reading) {
-        return fallback;
-    }
+            part += String.fromCodePoint(c);
+        }
 
-    let isAmbiguous = false;
-    const segmentize = (reading2, groups) => {
-        if (groups.length === 0 || isAmbiguous) {
-            return [];
+        if (part.length > 0) {
+            result += convertAlphabeticPartToKana(part, sourceMap, result.length);
         }
+        return result;
+    }
 
-        const group = groups[0];
-        if (group.mode === 'kana') {
-            if (jpKatakanaToHiragana(reading2).startsWith(jpKatakanaToHiragana(group.text))) {
-                const readingLeft = reading2.substring(group.text.length);
-                const segs = segmentize(readingLeft, groups.splice(1));
-                if (segs) {
-                    return [{text: group.text}].concat(segs);
-                }
-            }
-        } else {
-            let foundSegments = null;
-            for (let i = reading2.length; i >= group.text.length; --i) {
-                const readingUsed = reading2.substring(0, i);
-                const readingLeft = reading2.substring(i);
-                const segs = segmentize(readingLeft, groups.slice(1));
-                if (segs) {
-                    if (foundSegments !== null) {
-                        // more than one way to segmentize the tail, mark as ambiguous
-                        isAmbiguous = true;
-                        return null;
+    function convertAlphabeticPartToKana(text, sourceMap, sourceMapStart) {
+        const result = wanakana.toHiragana(text);
+
+        // Generate source mapping
+        if (sourceMap !== null) {
+            let i = 0;
+            let resultPos = 0;
+            const ii = text.length;
+            while (i < ii) {
+                // Find smallest matching substring
+                let iNext = i + 1;
+                let resultPosNext = result.length;
+                while (iNext < ii) {
+                    const t = wanakana.toHiragana(text.substring(0, iNext));
+                    if (t === result.substring(0, t.length)) {
+                        resultPosNext = t.length;
+                        break;
                     }
-                    foundSegments = [{text: group.text, furigana: readingUsed}].concat(segs);
+                    ++iNext;
                 }
-                // there is only one way to segmentize the last non-kana group
-                if (groups.length === 1) {
-                    break;
+
+                // Merge characters
+                const removals = iNext - i - 1;
+                if (removals > 0) {
+                    sourceMap.combine(sourceMapStart, removals);
+                }
+                ++sourceMapStart;
+
+                // Empty elements
+                const additions = resultPosNext - resultPos - 1;
+                for (let j = 0; j < additions; ++j) {
+                    sourceMap.insert(sourceMapStart, 0);
+                    ++sourceMapStart;
                 }
+
+                i = iNext;
+                resultPos = resultPosNext;
             }
-            return foundSegments;
-        }
-    };
-
-    const groups = [];
-    let modePrev = null;
-    for (const c of expression) {
-        const codePoint = c.codePointAt(0);
-        const modeCurr = jpIsCodePointKanji(codePoint) || codePoint === JP_ITERATION_MARK_CHAR_CODE ? 'kanji' : 'kana';
-        if (modeCurr === modePrev) {
-            groups[groups.length - 1].text += c;
-        } else {
-            groups.push({mode: modeCurr, text: c});
-            modePrev = modeCurr;
         }
-    }
 
-    const segments = segmentize(reading, groups);
-    if (segments && !isAmbiguous) {
-        return segments;
-    }
-    return fallback;
-}
-
-function jpDistributeFuriganaInflected(expression, reading, source) {
-    const output = [];
-
-    let stemLength = 0;
-    const shortest = Math.min(source.length, expression.length);
-    const sourceHiragana = jpKatakanaToHiragana(source);
-    const expressionHiragana = jpKatakanaToHiragana(expression);
-    while (stemLength < shortest && sourceHiragana[stemLength] === expressionHiragana[stemLength]) {
-        ++stemLength;
-    }
-    const offset = source.length - stemLength;
-
-    const stemExpression = source.substring(0, source.length - offset);
-    const stemReading = reading.substring(
-        0,
-        offset === 0 ? reading.length : reading.length - expression.length + stemLength
-    );
-    for (const segment of jpDistributeFurigana(stemExpression, stemReading)) {
-        output.push(segment);
+        return result;
     }
 
-    if (stemLength !== source.length) {
-        output.push({text: source.substring(stemLength)});
-    }
 
-    return output;
-}
-
-function jpConvertHalfWidthKanaToFullWidth(text, sourceMapping) {
-    let result = '';
-    const hasSourceMapping = Array.isArray(sourceMapping);
-
-    // This function is safe to use charCodeAt instead of codePointAt, since all
-    // the relevant characters are represented with a single UTF-16 character code.
-    for (let i = 0, ii = text.length; i < ii; ++i) {
-        const c = text[i];
-        const mapping = JP_HALFWIDTH_KATAKANA_MAPPING.get(c);
-        if (typeof mapping !== 'string') {
-            result += c;
-            continue;
-        }
+    // Furigana distribution
 
-        let index = 0;
-        switch (text.charCodeAt(i + 1)) {
-            case 0xff9e: // dakuten
-                index = 1;
-                break;
-            case 0xff9f: // handakuten
-                index = 2;
-                break;
+    function distributeFurigana(expression, reading) {
+        const fallback = [{furigana: reading, text: expression}];
+        if (!reading) {
+            return fallback;
         }
 
-        let c2 = mapping[index];
-        if (index > 0) {
-            if (c2 === '-') { // invalid
-                index = 0;
-                c2 = mapping[0];
-            } else {
-                ++i;
+        let isAmbiguous = false;
+        const segmentize = (reading2, groups) => {
+            if (groups.length === 0 || isAmbiguous) {
+                return [];
             }
-        }
 
-        if (hasSourceMapping && index > 0) {
-            index = result.length;
-            const v = sourceMapping.splice(index + 1, 1)[0];
-            sourceMapping[index] += v;
+            const group = groups[0];
+            if (group.mode === 'kana') {
+                if (convertKatakanaToHiragana(reading2).startsWith(convertKatakanaToHiragana(group.text))) {
+                    const readingLeft = reading2.substring(group.text.length);
+                    const segs = segmentize(readingLeft, groups.splice(1));
+                    if (segs) {
+                        return [{text: group.text}].concat(segs);
+                    }
+                }
+            } else {
+                let foundSegments = null;
+                for (let i = reading2.length; i >= group.text.length; --i) {
+                    const readingUsed = reading2.substring(0, i);
+                    const readingLeft = reading2.substring(i);
+                    const segs = segmentize(readingLeft, groups.slice(1));
+                    if (segs) {
+                        if (foundSegments !== null) {
+                            // more than one way to segmentize the tail, mark as ambiguous
+                            isAmbiguous = true;
+                            return null;
+                        }
+                        foundSegments = [{text: group.text, furigana: readingUsed}].concat(segs);
+                    }
+                    // there is only one way to segmentize the last non-kana group
+                    if (groups.length === 1) {
+                        break;
+                    }
+                }
+                return foundSegments;
+            }
+        };
+
+        const groups = [];
+        let modePrev = null;
+        for (const c of expression) {
+            const codePoint = c.codePointAt(0);
+            const modeCurr = isCodePointKanji(codePoint) || codePoint === ITERATION_MARK_CODE_POINT ? 'kanji' : 'kana';
+            if (modeCurr === modePrev) {
+                groups[groups.length - 1].text += c;
+            } else {
+                groups.push({mode: modeCurr, text: c});
+                modePrev = modeCurr;
+            }
         }
-        result += c2;
-    }
 
-    return result;
-}
-
-function jpConvertNumericTofullWidth(text) {
-    let result = '';
-    for (const char of text) {
-        let c = char.codePointAt(0);
-        if (c >= 0x30 && c <= 0x39) { // ['0', '9']
-            c += 0xff10 - 0x30; // 0xff10 = '0' full width
-            result += String.fromCodePoint(c);
-        } else {
-            result += char;
+        const segments = segmentize(reading, groups);
+        if (segments && !isAmbiguous) {
+            return segments;
         }
+        return fallback;
     }
-    return result;
-}
 
-function jpConvertAlphabeticToKana(text, sourceMapping) {
-    let part = '';
-    let result = '';
-    const ii = text.length;
+    function distributeFuriganaInflected(expression, reading, source) {
+        const output = [];
 
-    if (sourceMapping.length === ii) {
-        sourceMapping.length = ii;
-        sourceMapping.fill(1);
-    }
+        let stemLength = 0;
+        const shortest = Math.min(source.length, expression.length);
+        const sourceHiragana = convertKatakanaToHiragana(source);
+        const expressionHiragana = convertKatakanaToHiragana(expression);
+        while (stemLength < shortest && sourceHiragana[stemLength] === expressionHiragana[stemLength]) {
+            ++stemLength;
+        }
+        const offset = source.length - stemLength;
+
+        const stemExpression = source.substring(0, source.length - offset);
+        const stemReading = reading.substring(
+            0,
+            offset === 0 ? reading.length : reading.length - expression.length + stemLength
+        );
+        for (const segment of distributeFurigana(stemExpression, stemReading)) {
+            output.push(segment);
+        }
 
-    for (const char of text) {
-        // Note: 0x61 is the character code for 'a'
-        let c = char.codePointAt(0);
-        if (c >= 0x41 && c <= 0x5a) { // ['A', 'Z']
-            c += (0x61 - 0x41);
-        } else if (c >= 0x61 && c <= 0x7a) { // ['a', 'z']
-            // NOP; c += (0x61 - 0x61);
-        } else if (c >= 0xff21 && c <= 0xff3a) { // ['A', 'Z'] fullwidth
-            c += (0x61 - 0xff21);
-        } else if (c >= 0xff41 && c <= 0xff5a) { // ['a', 'z'] fullwidth
-            c += (0x61 - 0xff41);
-        } else if (c === 0x2d || c === 0xff0d) { // '-' or fullwidth dash
-            c = 0x2d; // '-'
-        } else {
-            if (part.length > 0) {
-                result += jpToHiragana(part, sourceMapping, result.length);
-                part = '';
-            }
-            result += char;
-            continue;
+        if (stemLength !== source.length) {
+            output.push({text: source.substring(stemLength)});
         }
-        part += String.fromCodePoint(c);
-    }
 
-    if (part.length > 0) {
-        result += jpToHiragana(part, sourceMapping, result.length);
+        return output;
     }
-    return result;
-}
-
-function jpToHiragana(text, sourceMapping, sourceMappingStart) {
-    const result = wanakana.toHiragana(text);
-
-    // Generate source mapping
-    if (Array.isArray(sourceMapping)) {
-        if (typeof sourceMappingStart !== 'number') { sourceMappingStart = 0; }
-        let i = 0;
-        let resultPos = 0;
-        const ii = text.length;
-        while (i < ii) {
-            // Find smallest matching substring
-            let iNext = i + 1;
-            let resultPosNext = result.length;
-            while (iNext < ii) {
-                const t = wanakana.toHiragana(text.substring(0, iNext));
-                if (t === result.substring(0, t.length)) {
-                    resultPosNext = t.length;
-                    break;
-                }
-                ++iNext;
-            }
-
-            // Merge characters
-            const removals = iNext - i - 1;
-            if (removals > 0) {
-                let sum = 0;
-                const vs = sourceMapping.splice(sourceMappingStart + 1, removals);
-                for (const v of vs) { sum += v; }
-                sourceMapping[sourceMappingStart] += sum;
-            }
-            ++sourceMappingStart;
 
-            // Empty elements
-            const additions = resultPosNext - resultPos - 1;
-            for (let j = 0; j < additions; ++j) {
-                sourceMapping.splice(sourceMappingStart, 0, 0);
-                ++sourceMappingStart;
-            }
-
-            i = iNext;
-            resultPos = resultPosNext;
-        }
-    }
 
-    return result;
-}
+    // Exports
+
+    Object.assign(jp, {
+        convertKatakanaToHiragana,
+        convertHiraganaToKatakana,
+        convertToRomaji,
+        convertReading,
+        convertNumericToFullWidth,
+        convertHalfWidthKanaToFullWidth,
+        convertAlphabeticToKana,
+        distributeFurigana,
+        distributeFuriganaInflected
+    });
+})();
diff --git a/ext/bg/js/options.js b/ext/bg/js/options.js
index bd0bbe0e..abb054d4 100644
--- a/ext/bg/js/options.js
+++ b/ext/bg/js/options.js
@@ -91,6 +91,15 @@ const profileOptionsVersionUpdates = [
         if (utilStringHashCode(options.anki.fieldTemplates) === 1444379824) {
             options.anki.fieldTemplates = null;
         }
+    },
+    (options) => {
+        // Version 13 changes:
+        //  Default anki field tempaltes updated to include {document-title}.
+        let fieldTemplates = options.anki.fieldTemplates;
+        if (typeof fieldTemplates === 'string') {
+            fieldTemplates += '\n\n{{#*inline "document-title"}}\n    {{~context.document.title~}}\n{{/inline}}';
+            options.anki.fieldTemplates = fieldTemplates;
+        }
     }
 ];
 
@@ -124,7 +133,11 @@ function profileOptionsCreateDefaults() {
             customPopupCss: '',
             customPopupOuterCss: '',
             enableWanakana: true,
-            enableClipboardMonitor: false
+            enableClipboardMonitor: false,
+            showPitchAccentDownstepNotation: true,
+            showPitchAccentPositionNotation: true,
+            showPitchAccentGraph: false,
+            showIframePopupsInRootFrame: false
         },
 
         audio: {
diff --git a/ext/bg/js/search-frontend.js b/ext/bg/js/search-frontend.js
index a470e873..f130a6fa 100644
--- a/ext/bg/js/search-frontend.js
+++ b/ext/bg/js/search-frontend.js
@@ -30,16 +30,12 @@ async function searchFrontendSetup() {
     const options = await apiOptionsGet(optionsContext);
     if (!options.scanning.enableOnSearchPage) { return; }
 
-    const ignoreNodes = ['.scan-disable', '.scan-disable *'];
-    if (!options.scanning.enableOnPopupExpressions) {
-        ignoreNodes.push('.source-text', '.source-text *');
-    }
-
-    window.frontendInitializationData = {depth: 1, ignoreNodes, proxy: false};
+    window.frontendInitializationData = {depth: 1, proxy: false};
 
     const scriptSrcs = [
         '/mixed/js/text-scanner.js',
         '/fg/js/frontend-api-receiver.js',
+        '/fg/js/frame-offset-forwarder.js',
         '/fg/js/popup.js',
         '/fg/js/popup-proxy-host.js',
         '/fg/js/frontend.js',
diff --git a/ext/bg/js/search-query-parser.js b/ext/bg/js/search-query-parser.js
index 06316ce2..9f59f2e5 100644
--- a/ext/bg/js/search-query-parser.js
+++ b/ext/bg/js/search-query-parser.js
@@ -27,12 +27,14 @@
  */
 
 class QueryParser extends TextScanner {
-    constructor(search) {
-        super(document.querySelector('#query-parser-content'), [], [], []);
-        this.search = search;
+    constructor({getOptionsContext, setContent, setSpinnerVisible}) {
+        super(document.querySelector('#query-parser-content'), [], []);
+
+        this.getOptionsContext = getOptionsContext;
+        this.setContent = setContent;
+        this.setSpinnerVisible = setSpinnerVisible;
 
         this.parseResults = [];
-        this.selectedParser = null;
 
         this.queryParser = document.querySelector('#query-parser-content');
         this.queryParserSelect = document.querySelector('#query-parser-select-container');
@@ -56,18 +58,18 @@ class QueryParser extends TextScanner {
     async onSearchSource(textSource, cause) {
         if (textSource === null) { return null; }
 
-        this.setTextSourceScanLength(textSource, this.search.options.scanning.length);
+        this.setTextSourceScanLength(textSource, this.options.scanning.length);
         const searchText = textSource.text();
         if (searchText.length === 0) { return; }
 
-        const {definitions, length} = await apiTermsFind(searchText, {}, this.search.getOptionsContext());
+        const {definitions, length} = await apiTermsFind(searchText, {}, this.getOptionsContext());
         if (definitions.length === 0) { return null; }
 
-        const sentence = docSentenceExtract(textSource, this.search.options.anki.sentenceExt);
+        const sentence = docSentenceExtract(textSource, this.options.anki.sentenceExt);
 
         textSource.setEndOffset(length);
 
-        this.search.setContent('terms', {definitions, context: {
+        this.setContent('terms', {definitions, context: {
             focus: false,
             disableHistory: cause === 'mouse',
             sentence,
@@ -79,9 +81,7 @@ class QueryParser extends TextScanner {
 
     onParserChange(e) {
         const selectedParser = e.target.value;
-        this.selectedParser = selectedParser;
-        apiOptionsSet({parsing: {selectedParser}}, this.search.getOptionsContext());
-        this.renderParseResult();
+        apiOptionsSet({parsing: {selectedParser}}, this.getOptionsContext());
     }
 
     getMouseEventListeners() {
@@ -112,23 +112,20 @@ class QueryParser extends TextScanner {
 
     refreshSelectedParser() {
         if (this.parseResults.length > 0) {
-            if (this.selectedParser === null) {
-                this.selectedParser = this.search.options.parsing.selectedParser;
-            }
-            if (this.selectedParser === null || !this.getParseResult()) {
+            if (!this.getParseResult()) {
                 const selectedParser = this.parseResults[0].id;
-                this.selectedParser = selectedParser;
-                apiOptionsSet({parsing: {selectedParser}}, this.search.getOptionsContext());
+                apiOptionsSet({parsing: {selectedParser}}, this.getOptionsContext());
             }
         }
     }
 
     getParseResult() {
-        return this.parseResults.find((r) => r.id === this.selectedParser);
+        const {selectedParser} = this.options.parsing;
+        return this.parseResults.find((r) => r.id === selectedParser);
     }
 
     async setText(text) {
-        this.search.setSpinnerVisible(true);
+        this.setSpinnerVisible(true);
 
         this.setPreview(text);
 
@@ -138,20 +135,20 @@ class QueryParser extends TextScanner {
         this.renderParserSelect();
         this.renderParseResult();
 
-        this.search.setSpinnerVisible(false);
+        this.setSpinnerVisible(false);
     }
 
     async parseText(text) {
         const results = [];
-        if (this.search.options.parsing.enableScanningParser) {
+        if (this.options.parsing.enableScanningParser) {
             results.push({
                 name: 'Scanning parser',
                 id: 'scan',
-                parsedText: await apiTextParse(text, this.search.getOptionsContext())
+                parsedText: await apiTextParse(text, this.getOptionsContext())
             });
         }
-        if (this.search.options.parsing.enableMecabParser) {
-            const mecabResults = await apiTextParseMecab(text, this.search.getOptionsContext());
+        if (this.options.parsing.enableMecabParser) {
+            const mecabResults = await apiTextParseMecab(text, this.getOptionsContext());
             for (const [mecabDictName, mecabDictResults] of mecabResults) {
                 results.push({
                     name: `MeCab: ${mecabDictName}`,
@@ -176,7 +173,8 @@ class QueryParser extends TextScanner {
     renderParserSelect() {
         this.queryParserSelect.textContent = '';
         if (this.parseResults.length > 1) {
-            const select = this.queryParserGenerator.createParserSelect(this.parseResults, this.selectedParser);
+            const {selectedParser} = this.options.parsing;
+            const select = this.queryParserGenerator.createParserSelect(this.parseResults, selectedParser);
             select.addEventListener('change', this.onParserChange.bind(this));
             this.queryParserSelect.appendChild(select);
         }
diff --git a/ext/bg/js/search.js b/ext/bg/js/search.js
index e2bdff73..9250fdde 100644
--- a/ext/bg/js/search.js
+++ b/ext/bg/js/search.js
@@ -29,12 +29,18 @@ class DisplaySearch extends Display {
     constructor() {
         super(document.querySelector('#spinner'), document.querySelector('#content'));
 
+        this._isPrepared = false;
+
         this.optionsContext = {
             depth: 0,
             url: window.location.href
         };
 
-        this.queryParser = new QueryParser(this);
+        this.queryParser = new QueryParser({
+            getOptionsContext: this.getOptionsContext.bind(this),
+            setContent: this.setContent.bind(this),
+            setSpinnerVisible: this.setSpinnerVisible.bind(this)
+        });
 
         this.search = document.querySelector('#search');
         this.query = document.querySelector('#query');
@@ -112,6 +118,8 @@ class DisplaySearch extends Display {
             this.clipboardMonitor.on('change', this.onExternalSearchUpdate.bind(this));
 
             this.updateSearchButton();
+
+            this._isPrepared = true;
         } catch (e) {
             this.onError(e);
         }
@@ -247,15 +255,12 @@ class DisplaySearch extends Display {
     }
 
     onWanakanaEnableChange(e) {
-        const {queryParams: {query=''}} = parseUrl(window.location.href);
         const enableWanakana = e.target.checked;
         if (enableWanakana) {
             window.wanakana.bind(this.query);
         } else {
             window.wanakana.unbind(this.query);
         }
-        this.setQuery(query);
-        this.onSearchQueryUpdated(this.query.value, false);
         apiOptionsSet({general: {enableWanakana}}, this.getOptionsContext());
     }
 
@@ -278,19 +283,21 @@ class DisplaySearch extends Display {
         }
     }
 
-    async updateOptions(options) {
-        await super.updateOptions(options);
+    async updateOptions() {
+        await super.updateOptions();
         this.queryParser.setOptions(this.options);
+        if (!this._isPrepared) { return; }
+        const query = this.query.value;
+        if (query) {
+            this.setQuery(query);
+            this.onSearchQueryUpdated(query, false);
+        }
     }
 
     isWanakanaEnabled() {
         return this.wanakanaEnable !== null && this.wanakanaEnable.checked;
     }
 
-    getOptionsContext() {
-        return this.optionsContext;
-    }
-
     setQuery(query) {
         const interpretedQuery = this.isWanakanaEnabled() ? window.wanakana.toKana(query) : query;
         this.query.value = interpretedQuery;
diff --git a/ext/bg/js/settings/anki-templates.js b/ext/bg/js/settings/anki-templates.js
index c5222d30..e3852eb4 100644
--- a/ext/bg/js/settings/anki-templates.js
+++ b/ext/bg/js/settings/anki-templates.js
@@ -99,10 +99,15 @@ async function ankiTemplatesValidate(infoNode, field, mode, showSuccessResult, i
         const definition = await ankiTemplatesValidateGetDefinition(text, optionsContext);
         if (definition !== null) {
             const options = await apiOptionsGet(optionsContext);
+            const context = {
+                document: {
+                    title: document.title
+                }
+            };
             let templates = options.anki.fieldTemplates;
             if (typeof templates !== 'string') { templates = await apiGetDefaultAnkiFieldTemplates(); }
             const ankiNoteBuilder = new AnkiNoteBuilder({renderTemplate: apiTemplateRender});
-            result = await ankiNoteBuilder.formatField(field, definition, mode, options, templates, exceptions);
+            result = await ankiNoteBuilder.formatField(field, definition, mode, context, options, templates, exceptions);
         }
     } catch (e) {
         exceptions.push(e);
diff --git a/ext/bg/js/settings/anki.js b/ext/bg/js/settings/anki.js
index b706cd1b..f2e1ca76 100644
--- a/ext/bg/js/settings/anki.js
+++ b/ext/bg/js/settings/anki.js
@@ -243,6 +243,7 @@ function ankiGetFieldMarkers(type) {
                 'cloze-prefix',
                 'cloze-suffix',
                 'dictionary',
+                'document-title',
                 'expression',
                 'furigana',
                 'furigana-plain',
@@ -258,6 +259,7 @@ function ankiGetFieldMarkers(type) {
             return [
                 'character',
                 'dictionary',
+                'document-title',
                 'glossary',
                 'kunyomi',
                 'onyomi',
diff --git a/ext/bg/js/settings/dictionaries.js b/ext/bg/js/settings/dictionaries.js
index 5e59cc3d..33ced3b9 100644
--- a/ext/bg/js/settings/dictionaries.js
+++ b/ext/bg/js/settings/dictionaries.js
@@ -199,11 +199,16 @@ class SettingsDictionaryEntryUI {
         this.allowSecondarySearchesCheckbox = this.content.querySelector('.dict-allow-secondary-searches');
         this.priorityInput = this.content.querySelector('.dict-priority');
         this.deleteButton = this.content.querySelector('.dict-delete-button');
+        this.detailsToggleLink = this.content.querySelector('.dict-details-toggle-link');
+        this.detailsContainer = this.content.querySelector('.dict-details');
+        this.detailsTable = this.content.querySelector('.dict-details-table');
 
         if (this.dictionaryInfo.version < 3) {
             this.content.querySelector('.dict-outdated').hidden = false;
         }
 
+        this.setupDetails(dictionaryInfo);
+
         this.content.querySelector('.dict-title').textContent = this.dictionaryInfo.title;
         this.content.querySelector('.dict-revision').textContent = `rev.${this.dictionaryInfo.revision}`;
         this.content.querySelector('.dict-prefix-wildcard-searches-supported').checked = !!this.dictionaryInfo.prefixWildcardsSupported;
@@ -214,6 +219,45 @@ class SettingsDictionaryEntryUI {
         this.eventListeners.addEventListener(this.allowSecondarySearchesCheckbox, 'change', this.onAllowSecondarySearchesChanged.bind(this), false);
         this.eventListeners.addEventListener(this.priorityInput, 'change', this.onPriorityChanged.bind(this), false);
         this.eventListeners.addEventListener(this.deleteButton, 'click', this.onDeleteButtonClicked.bind(this), false);
+        this.eventListeners.addEventListener(this.detailsToggleLink, 'click', this.onDetailsToggleLinkClicked.bind(this), false);
+    }
+
+    setupDetails(dictionaryInfo) {
+        const targets = [
+            ['Author', 'author'],
+            ['URL', 'url'],
+            ['Description', 'description'],
+            ['Attribution', 'attribution']
+        ];
+
+        let count = 0;
+        for (const [label, key] of targets) {
+            const info = dictionaryInfo[key];
+            if (typeof info !== 'string') { continue; }
+
+            const n1 = document.createElement('div');
+            n1.className = 'dict-details-entry';
+            n1.dataset.type = key;
+
+            const n2 = document.createElement('span');
+            n2.className = 'dict-details-entry-label';
+            n2.textContent = `${label}:`;
+            n1.appendChild(n2);
+
+            const n3 = document.createElement('span');
+            n3.className = 'dict-details-entry-info';
+            n3.textContent = info;
+            n1.appendChild(n3);
+
+            this.detailsTable.appendChild(n1);
+
+            ++count;
+        }
+
+        if (count === 0) {
+            this.detailsContainer.hidden = true;
+            this.detailsToggleLink.hidden = true;
+        }
     }
 
     cleanup() {
@@ -318,6 +362,12 @@ class SettingsDictionaryEntryUI {
         document.querySelector('#dict-remove-modal-dict-name').textContent = title;
         $(n).modal('show');
     }
+
+    onDetailsToggleLinkClicked(e) {
+        e.preventDefault();
+
+        this.detailsContainer.hidden = !this.detailsContainer.hidden;
+    }
 }
 
 class SettingsDictionaryExtraUI {
@@ -505,7 +555,7 @@ function dictionaryErrorsShow(errors) {
     if (errors !== null && errors.length > 0) {
         const uniqueErrors = new Map();
         for (let e of errors) {
-            console.error(e);
+            logError(e);
             e = dictionaryErrorToString(e);
             let count = uniqueErrors.get(e);
             if (typeof count === 'undefined') {
@@ -643,9 +693,9 @@ async function onDictionaryImport(e) {
             await settingsSaveOptions();
 
             if (errors.length > 0) {
-                errors.push(...errors);
-                errors.push(`Dictionary may not have been imported properly: ${errors.length} error${errors.length === 1 ? '' : 's'} reported.`);
-                dictionaryErrorsShow(errors);
+                const errors2 = errors.map((error) => jsonToError(error));
+                errors2.push(`Dictionary may not have been imported properly: ${errors2.length} error${errors2.length === 1 ? '' : 's'} reported.`);
+                dictionaryErrorsShow(errors2);
             }
 
             onDatabaseUpdated();
diff --git a/ext/bg/js/settings/main.js b/ext/bg/js/settings/main.js
index ebc443df..1653ee35 100644
--- a/ext/bg/js/settings/main.js
+++ b/ext/bg/js/settings/main.js
@@ -84,6 +84,10 @@ async function formRead(options) {
     options.general.popupScalingFactor = parseFloat($('#popup-scaling-factor').val());
     options.general.popupScaleRelativeToPageZoom = $('#popup-scale-relative-to-page-zoom').prop('checked');
     options.general.popupScaleRelativeToVisualViewport = $('#popup-scale-relative-to-visual-viewport').prop('checked');
+    options.general.showPitchAccentDownstepNotation = $('#show-pitch-accent-downstep-notation').prop('checked');
+    options.general.showPitchAccentPositionNotation = $('#show-pitch-accent-position-notation').prop('checked');
+    options.general.showPitchAccentGraph = $('#show-pitch-accent-graph').prop('checked');
+    options.general.showIframePopupsInRootFrame = $('#show-iframe-popups-in-root-frame').prop('checked');
     options.general.popupTheme = $('#popup-theme').val();
     options.general.popupOuterTheme = $('#popup-outer-theme').val();
     options.general.customPopupCss = $('#custom-popup-css').val();
@@ -161,6 +165,10 @@ async function formWrite(options) {
     $('#popup-scaling-factor').val(options.general.popupScalingFactor);
     $('#popup-scale-relative-to-page-zoom').prop('checked', options.general.popupScaleRelativeToPageZoom);
     $('#popup-scale-relative-to-visual-viewport').prop('checked', options.general.popupScaleRelativeToVisualViewport);
+    $('#show-pitch-accent-downstep-notation').prop('checked', options.general.showPitchAccentDownstepNotation);
+    $('#show-pitch-accent-position-notation').prop('checked', options.general.showPitchAccentPositionNotation);
+    $('#show-pitch-accent-graph').prop('checked', options.general.showPitchAccentGraph);
+    $('#show-iframe-popups-in-root-frame').prop('checked', options.general.showIframePopupsInRootFrame);
     $('#popup-theme').val(options.general.popupTheme);
     $('#popup-outer-theme').val(options.general.popupOuterTheme);
     $('#custom-popup-css').val(options.general.customPopupCss);
diff --git a/ext/bg/js/text-source-map.js b/ext/bg/js/text-source-map.js
new file mode 100644
index 00000000..24970978
--- /dev/null
+++ b/ext/bg/js/text-source-map.js
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+class TextSourceMap {
+    constructor(source, mapping=null) {
+        this._source = source;
+        this._mapping = (Array.isArray(mapping) ? TextSourceMap._normalizeMapping(mapping) : null);
+    }
+
+    get source() {
+        return this._source;
+    }
+
+    equals(other) {
+        if (this === other) {
+            return true;
+        }
+
+        const source = this._source;
+        if (!(other instanceof TextSourceMap && source === other._source)) {
+            return false;
+        }
+
+        let mapping = this._mapping;
+        let otherMapping = other._mapping;
+        if (mapping === null) {
+            if (otherMapping === null) {
+                return true;
+            }
+            mapping = TextSourceMap._createMapping(source);
+        } else if (otherMapping === null) {
+            otherMapping = TextSourceMap._createMapping(source);
+        }
+
+        const mappingLength = mapping.length;
+        if (mappingLength !== otherMapping.length) {
+            return false;
+        }
+
+        for (let i = 0; i < mappingLength; ++i) {
+            if (mapping[i] !== otherMapping[i]) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    getSourceLength(finalLength) {
+        const mapping = this._mapping;
+        if (mapping === null) {
+            return finalLength;
+        }
+
+        let sourceLength = 0;
+        for (let i = 0; i < finalLength; ++i) {
+            sourceLength += mapping[i];
+        }
+        return sourceLength;
+    }
+
+    combine(index, count) {
+        if (count <= 0) { return; }
+
+        if (this._mapping === null) {
+            this._mapping = TextSourceMap._createMapping(this._source);
+        }
+
+        let sum = this._mapping[index];
+        const parts = this._mapping.splice(index + 1, count);
+        for (const part of parts) {
+            sum += part;
+        }
+        this._mapping[index] = sum;
+    }
+
+    insert(index, ...items) {
+        if (this._mapping === null) {
+            this._mapping = TextSourceMap._createMapping(this._source);
+        }
+
+        this._mapping.splice(index, 0, ...items);
+    }
+
+    static _createMapping(text) {
+        return new Array(text.length).fill(1);
+    }
+
+    static _normalizeMapping(mapping) {
+        const result = [];
+        for (const value of mapping) {
+            result.push(
+                (typeof value === 'number' && Number.isFinite(value)) ?
+                Math.floor(value) :
+                0
+            );
+        }
+        return result;
+    }
+}
diff --git a/ext/bg/js/translator.js b/ext/bg/js/translator.js
index 25da9bf0..27f91c05 100644
--- a/ext/bg/js/translator.js
+++ b/ext/bg/js/translator.js
@@ -17,8 +17,8 @@
  */
 
 /* global
- * Database
  * Deinflector
+ * TextSourceMap
  * dictEnabledSet
  * dictTagBuildSource
  * dictTagSanitize
@@ -29,34 +29,21 @@
  * dictTermsMergeBySequence
  * dictTermsSort
  * dictTermsUndupe
- * jpConvertAlphabeticToKana
- * jpConvertHalfWidthKanaToFullWidth
- * jpConvertNumericTofullWidth
- * jpDistributeFurigana
- * jpHiraganaToKatakana
- * jpIsCodePointJapanese
- * jpKatakanaToHiragana
+ * jp
  * requestJson
  */
 
 class Translator {
-    constructor() {
-        this.database = null;
+    constructor(database) {
+        this.database = database;
         this.deinflector = null;
         this.tagCache = new Map();
     }
 
     async prepare() {
-        if (!this.database) {
-            this.database = new Database();
-            await this.database.prepare();
-        }
-
-        if (!this.deinflector) {
-            const url = chrome.runtime.getURL('/bg/lang/deinflect.json');
-            const reasons = await requestJson(url, 'GET');
-            this.deinflector = new Deinflector(reasons);
-        }
+        const url = chrome.runtime.getURL('/bg/lang/deinflect.json');
+        const reasons = await requestJson(url, 'GET');
+        this.deinflector = new Deinflector(reasons);
     }
 
     async purgeDatabase() {
@@ -275,7 +262,7 @@ class Translator {
                 const termTags = await this.expandTags(definition.termTags, definition.dictionary);
 
                 const {expression, reading} = definition;
-                const furiganaSegments = jpDistributeFurigana(expression, reading);
+                const furiganaSegments = jp.distributeFurigana(expression, reading);
 
                 definitions.push({
                     source: deinflection.source,
@@ -373,23 +360,21 @@ class Translator {
         const used = new Set();
         for (const [halfWidth, numeric, alphabetic, katakana, hiragana] of Translator.getArrayVariants(textOptionVariantArray)) {
             let text2 = text;
-            let sourceMapping = null;
+            const sourceMap = new TextSourceMap(text2);
             if (halfWidth) {
-                if (sourceMapping === null) { sourceMapping = Translator.createTextSourceMapping(text2); }
-                text2 = jpConvertHalfWidthKanaToFullWidth(text2, sourceMapping);
+                text2 = jp.convertHalfWidthKanaToFullWidth(text2, sourceMap);
             }
             if (numeric) {
-                text2 = jpConvertNumericTofullWidth(text2);
+                text2 = jp.convertNumericToFullWidth(text2);
             }
             if (alphabetic) {
-                if (sourceMapping === null) { sourceMapping = Translator.createTextSourceMapping(text2); }
-                text2 = jpConvertAlphabeticToKana(text2, sourceMapping);
+                text2 = jp.convertAlphabeticToKana(text2, sourceMap);
             }
             if (katakana) {
-                text2 = jpHiraganaToKatakana(text2);
+                text2 = jp.convertHiraganaToKatakana(text2);
             }
             if (hiragana) {
-                text2 = jpKatakanaToHiragana(text2);
+                text2 = jp.convertKatakanaToHiragana(text2);
             }
 
             for (let i = text2.length; i > 0; --i) {
@@ -397,7 +382,7 @@ class Translator {
                 if (used.has(text2Substring)) { break; }
                 used.add(text2Substring);
                 for (const deinflection of this.deinflector.deinflect(text2Substring)) {
-                    deinflection.rawSource = Translator.getDeinflectionRawSource(text, i, sourceMapping);
+                    deinflection.rawSource = sourceMap.source.substring(0, sourceMap.getSourceLength(i));
                     deinflections.push(deinflection);
                 }
             }
@@ -413,25 +398,6 @@ class Translator {
         }
     }
 
-    static getDeinflectionRawSource(source, length, sourceMapping) {
-        if (sourceMapping === null) {
-            return source.substring(0, length);
-        }
-
-        let result = '';
-        let index = 0;
-        for (let i = 0; i < length; ++i) {
-            const c = sourceMapping[i];
-            result += source.substring(index, index + c);
-            index += c;
-        }
-        return result;
-    }
-
-    static createTextSourceMapping(text) {
-        return new Array(text.length).fill(1);
-    }
-
     async findKanji(text, options) {
         const dictionaries = dictEnabledSet(options);
         const kanjiUnique = new Set();
@@ -496,6 +462,7 @@ class Translator {
 
             // New data
             term.frequencies = [];
+            term.pitches = [];
         }
 
         const metas = await this.database.findTermMetaBulk(expressionsUnique, dictionaries);
@@ -506,6 +473,13 @@ class Translator {
                         term.frequencies.push({expression, frequency: data, dictionary});
                     }
                     break;
+                case 'pitch':
+                    for (const term of termsUnique[index]) {
+                        const pitchData = await this.getPitchData(expression, data, dictionary, term);
+                        if (pitchData === null) { continue; }
+                        term.pitches.push(pitchData);
+                    }
+                    break;
             }
         }
     }
@@ -589,8 +563,22 @@ class Translator {
         return tagMetaList;
     }
 
+    async getPitchData(expression, data, dictionary, term) {
+        const reading = data.reading;
+        const termReading = term.reading || expression;
+        if (reading !== termReading) { return null; }
+
+        const pitches = [];
+        for (let {position, tags} of data.pitches) {
+            tags = Array.isArray(tags) ? await this.getTagMetaList(tags, dictionary) : [];
+            pitches.push({position, tags});
+        }
+
+        return {reading, pitches, dictionary};
+    }
+
     static createExpression(expression, reading, termTags=null, termFrequency=null) {
-        const furiganaSegments = jpDistributeFurigana(expression, reading);
+        const furiganaSegments = jp.distributeFurigana(expression, reading);
         return {
             expression,
             reading,
@@ -639,7 +627,7 @@ class Translator {
         if (!options.scanning.alphanumeric) {
             let newText = '';
             for (const c of text) {
-                if (!jpIsCodePointJapanese(c.codePointAt(0))) {
+                if (!jp.isCodePointJapanese(c.codePointAt(0))) {
                     break;
                 }
                 newText += c;
diff --git a/ext/bg/js/util.js b/ext/bg/js/util.js
index 79c6af06..a7ed4a34 100644
--- a/ext/bg/js/util.js
+++ b/ext/bg/js/util.js
@@ -118,7 +118,7 @@ async function utilDatabaseDeleteDictionary(dictionaryName, onProgress) {
 
 async function utilDatabaseImport(data, onProgress, details) {
     data = await utilReadFile(data);
-    return utilIsolate(await utilBackend().translator.database.importDictionary(
+    return utilIsolate(await utilBackend().importDictionary(
         utilBackgroundIsolate(data),
         utilBackgroundFunctionIsolate(onProgress),
         utilBackgroundIsolate(details)
diff --git a/ext/bg/search.html b/ext/bg/search.html
index f4c1a737..eacc1893 100644
--- a/ext/bg/search.html
+++ b/ext/bg/search.html
@@ -74,6 +74,7 @@
         <script src="/mixed/js/core.js"></script>
         <script src="/mixed/js/dom.js"></script>
         <script src="/mixed/js/api.js"></script>
+        <script src="/mixed/js/japanese.js"></script>
 
         <script src="/bg/js/dictionary.js"></script>
         <script src="/bg/js/handlebars.js"></script>
diff --git a/ext/bg/settings.html b/ext/bg/settings.html
index 0db76d71..1297a9cc 100644
--- a/ext/bg/settings.html
+++ b/ext/bg/settings.html
@@ -163,6 +163,22 @@
                 </div>
 
                 <div class="checkbox options-advanced">
+                    <label><input type="checkbox" id="show-pitch-accent-downstep-notation"> Show downstep notation for pitch accents</label>
+                </div>
+
+                <div class="checkbox options-position">
+                    <label><input type="checkbox" id="show-pitch-accent-position-notation"> Show position notation for pitch accents</label>
+                </div>
+
+                <div class="checkbox options-advanced">
+                    <label><input type="checkbox" id="show-pitch-accent-graph"> Show graph for pitch accents</label>
+                </div>
+
+                <div class="checkbox options-advanced">
+                    <label><input type="checkbox" id="show-iframe-popups-in-root-frame"> Show iframe popups in root frame</label>
+                </div>
+
+                <div class="checkbox options-advanced">
                     <label><input type="checkbox" id="show-debug-info"> Show debug information</label>
                 </div>
 
@@ -658,6 +674,10 @@
                         <label class="dict-result-priority-label">Result priority</label>
                         <input type="number" class="form-control dict-priority">
                     </div>
+                    <div class="dict-details-container">
+                        <a class="dict-details-toggle-link">Details...</a>
+                        <div class="dict-details" hidden><div class="dict-details-table"></div></div>
+                    </div>
                     <div class="dict-delete-table">
                         <div>
                             <button class="btn btn-default dict-delete-button">Delete Dictionary</button>
@@ -1088,6 +1108,7 @@
         <script src="/mixed/js/core.js"></script>
         <script src="/mixed/js/dom.js"></script>
         <script src="/mixed/js/api.js"></script>
+        <script src="/mixed/js/japanese.js"></script>
 
         <script src="/bg/js/anki.js"></script>
         <script src="/bg/js/anki-note-builder.js"></script>
diff --git a/ext/fg/float.html b/ext/fg/float.html
index 7bbed565..3ccf68eb 100644
--- a/ext/fg/float.html
+++ b/ext/fg/float.html
@@ -43,6 +43,7 @@
         <script src="/mixed/js/core.js"></script>
         <script src="/mixed/js/dom.js"></script>
         <script src="/mixed/js/api.js"></script>
+        <script src="/mixed/js/japanese.js"></script>
 
         <script src="/fg/js/document.js"></script>
         <script src="/fg/js/source.js"></script>
diff --git a/ext/fg/js/float.js b/ext/fg/js/float.js
index 393c2719..01055ca6 100644
--- a/ext/fg/js/float.js
+++ b/ext/fg/js/float.js
@@ -28,6 +28,8 @@ class DisplayFloat extends Display {
         super(document.querySelector('#spinner'), document.querySelector('#definitions'));
         this.autoPlayAudioTimer = null;
 
+        this._popupId = null;
+
         this.optionsContext = {
             depth: 0,
             url: window.location.href
@@ -53,7 +55,7 @@ class DisplayFloat extends Display {
             ['setContent', ({type, details}) => this.setContent(type, details)],
             ['clearAutoPlayTimer', () => this.clearAutoPlayTimer()],
             ['setCustomCss', ({css}) => this.setCustomCss(css)],
-            ['prepare', ({options, popupInfo, url, childrenSupported, scale, uniqueId}) => this.prepare(options, popupInfo, url, childrenSupported, scale, uniqueId)],
+            ['prepare', ({popupInfo, url, childrenSupported, scale}) => this.prepare(popupInfo, url, childrenSupported, scale)],
             ['setContentScale', ({scale}) => this.setContentScale(scale)]
         ]);
 
@@ -61,23 +63,24 @@ class DisplayFloat extends Display {
         window.addEventListener('message', this.onMessage.bind(this), false);
     }
 
-    async prepare(options, popupInfo, url, childrenSupported, scale, uniqueId) {
+    async prepare(popupInfo, url, childrenSupported, scale) {
         if (this._prepareInvoked) { return; }
         this._prepareInvoked = true;
 
-        await super.prepare(options);
-
         const {id, depth, parentFrameId} = popupInfo;
+        this._popupId = id;
         this.optionsContext.depth = depth;
         this.optionsContext.url = url;
 
+        await super.prepare();
+
         if (childrenSupported) {
             popupNestedInitialize(id, depth, parentFrameId, url);
         }
 
         this.setContentScale(scale);
 
-        apiForward('popupPrepareCompleted', {uniqueId});
+        apiForward('popupPrepareCompleted', {targetPopupId: this._popupId});
     }
 
     onError(error) {
@@ -144,10 +147,6 @@ class DisplayFloat extends Display {
         handler(params);
     }
 
-    getOptionsContext() {
-        return this.optionsContext;
-    }
-
     autoPlayAudio() {
         this.clearAutoPlayTimer();
         this.autoPlayAudioTimer = window.setTimeout(() => super.autoPlayAudio(), 400);
@@ -163,6 +162,33 @@ class DisplayFloat extends Display {
     setContentScale(scale) {
         document.body.style.fontSize = `${scale}em`;
     }
+
+    async getDocumentTitle() {
+        try {
+            const uniqueId = yomichan.generateId(16);
+
+            const promise = yomichan.getTemporaryListenerResult(
+                chrome.runtime.onMessage,
+                ({action, params}, {resolve}) => {
+                    if (
+                        action === 'documentInformationBroadcast' &&
+                        isObject(params) &&
+                        params.uniqueId === uniqueId &&
+                        params.frameId === 0
+                    ) {
+                        resolve(params);
+                    }
+                },
+                2000
+            );
+            apiForward('requestDocumentInformationBroadcast', {uniqueId});
+
+            const {title} = await promise;
+            return title;
+        } catch (e) {
+            return '';
+        }
+    }
 }
 
 DisplayFloat.instance = new DisplayFloat();
diff --git a/ext/fg/js/frame-offset-forwarder.js b/ext/fg/js/frame-offset-forwarder.js
new file mode 100644
index 00000000..7b417b6e
--- /dev/null
+++ b/ext/fg/js/frame-offset-forwarder.js
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* global
+ * apiForward
+ */
+
+class FrameOffsetForwarder {
+    constructor() {
+        this._started = false;
+
+        this._forwardFrameOffset = (
+            window !== window.parent ?
+            this._forwardFrameOffsetParent.bind(this) :
+            this._forwardFrameOffsetOrigin.bind(this)
+        );
+
+        this._windowMessageHandlers = new Map([
+            ['getFrameOffset', ({offset, uniqueId}, e) => this._onGetFrameOffset(offset, uniqueId, e)]
+        ]);
+    }
+
+    start() {
+        if (this._started) { return; }
+        window.addEventListener('message', this.onMessage.bind(this), false);
+        this._started = true;
+    }
+
+    async getOffset() {
+        const uniqueId = yomichan.generateId(16);
+
+        const frameOffsetPromise = yomichan.getTemporaryListenerResult(
+            chrome.runtime.onMessage,
+            ({action, params}, {resolve}) => {
+                if (action === 'frameOffset' && isObject(params) && params.uniqueId === uniqueId) {
+                    resolve(params);
+                }
+            },
+            5000
+        );
+
+        window.parent.postMessage({
+            action: 'getFrameOffset',
+            params: {
+                uniqueId,
+                offset: [0, 0]
+            }
+        }, '*');
+
+        const {offset} = await frameOffsetPromise;
+        return offset;
+    }
+
+    onMessage(e) {
+        const {action, params} = e.data;
+        const handler = this._windowMessageHandlers.get(action);
+        if (typeof handler !== 'function') { return; }
+        handler(params, e);
+    }
+
+    _onGetFrameOffset(offset, uniqueId, e) {
+        let sourceFrame = null;
+        for (const frame of document.querySelectorAll('frame, iframe:not(.yomichan-float)')) {
+            if (frame.contentWindow !== e.source) { continue; }
+            sourceFrame = frame;
+            break;
+        }
+        if (sourceFrame === null) {
+            this._forwardFrameOffsetOrigin(null, uniqueId);
+            return;
+        }
+
+        const [forwardedX, forwardedY] = offset;
+        const {x, y} = sourceFrame.getBoundingClientRect();
+        offset = [forwardedX + x, forwardedY + y];
+
+        this._forwardFrameOffset(offset, uniqueId);
+    }
+
+    _forwardFrameOffsetParent(offset, uniqueId) {
+        window.parent.postMessage({action: 'getFrameOffset', params: {offset, uniqueId}}, '*');
+    }
+
+    _forwardFrameOffsetOrigin(offset, uniqueId) {
+        apiForward('frameOffset', {offset, uniqueId});
+    }
+}
diff --git a/ext/fg/js/frontend-initialize.js b/ext/fg/js/frontend-initialize.js
index 8424b21d..4a1409db 100644
--- a/ext/fg/js/frontend-initialize.js
+++ b/ext/fg/js/frontend-initialize.js
@@ -17,28 +17,56 @@
  */
 
 /* global
+ * FrameOffsetForwarder
  * Frontend
  * PopupProxy
  * PopupProxyHost
+ * apiForward
+ * apiOptionsGet
  */
 
 async function main() {
     await yomichan.prepare();
 
     const data = window.frontendInitializationData || {};
-    const {id, depth=0, parentFrameId, ignoreNodes, url, proxy=false} = data;
+    const {id, depth=0, parentFrameId, url, proxy=false} = data;
+
+    const optionsContext = {depth, url};
+    const options = await apiOptionsGet(optionsContext);
 
     let popup;
-    if (proxy) {
+    if (!proxy && (window !== window.parent) && options.general.showIframePopupsInRootFrame) {
+        const rootPopupInformationPromise = yomichan.getTemporaryListenerResult(
+            chrome.runtime.onMessage,
+            ({action, params}, {resolve}) => {
+                if (action === 'rootPopupInformation') {
+                    resolve(params);
+                }
+            }
+        );
+        apiForward('rootPopupRequestInformationBroadcast');
+        const {popupId, frameId} = await rootPopupInformationPromise;
+
+        const frameOffsetForwarder = new FrameOffsetForwarder();
+        frameOffsetForwarder.start();
+        const getFrameOffset = frameOffsetForwarder.getOffset.bind(frameOffsetForwarder);
+
+        popup = new PopupProxy(popupId, 0, null, frameId, url, getFrameOffset);
+        await popup.prepare();
+    } else if (proxy) {
         popup = new PopupProxy(null, depth + 1, id, parentFrameId, url);
+        await popup.prepare();
     } else {
+        const frameOffsetForwarder = new FrameOffsetForwarder();
+        frameOffsetForwarder.start();
+
         const popupHost = new PopupProxyHost();
         await popupHost.prepare();
 
         popup = popupHost.getOrCreatePopup(null, null, depth);
     }
 
-    const frontend = new Frontend(popup, ignoreNodes);
+    const frontend = new Frontend(popup);
     await frontend.prepare();
 }
 
diff --git a/ext/fg/js/frontend.js b/ext/fg/js/frontend.js
index 768b9326..31843212 100644
--- a/ext/fg/js/frontend.js
+++ b/ext/fg/js/frontend.js
@@ -18,6 +18,7 @@
 
 /* global
  * TextScanner
+ * apiForward
  * apiGetZoom
  * apiKanjiFind
  * apiOptionsGet
@@ -26,10 +27,9 @@
  */
 
 class Frontend extends TextScanner {
-    constructor(popup, ignoreNodes) {
+    constructor(popup) {
         super(
             window,
-            ignoreNodes,
             popup.isProxy() ? [] : [popup.getContainer()],
             [(x, y) => this.popup.containsPoint(x, y)]
         );
@@ -53,7 +53,9 @@ class Frontend extends TextScanner {
         ]);
 
         this._runtimeMessageHandlers = new Map([
-            ['popupSetVisibleOverride', ({visible}) => { this.popup.setVisibleOverride(visible); }]
+            ['popupSetVisibleOverride', ({visible}) => { this.popup.setVisibleOverride(visible); }],
+            ['rootPopupRequestInformationBroadcast', () => { this._broadcastRootPopupInformation(); }],
+            ['requestDocumentInformationBroadcast', ({uniqueId}) => { this._broadcastDocumentInformation(uniqueId); }]
         ]);
     }
 
@@ -77,6 +79,7 @@ class Frontend extends TextScanner {
             chrome.runtime.onMessage.addListener(this.onRuntimeMessage.bind(this));
 
             this._updateContentScale();
+            this._broadcastRootPopupInformation();
         } catch (e) {
             this.onError(e);
         }
@@ -95,6 +98,9 @@ class Frontend extends TextScanner {
     }
 
     onRuntimeMessage({action, params}, sender, callback) {
+        const {targetPopupId} = params || {};
+        if (typeof targetPopupId !== 'undefined' && targetPopupId !== this.popup.id) { return; }
+
         const handler = this._runtimeMessageHandlers.get(action);
         if (typeof handler !== 'function') { return false; }
 
@@ -129,8 +135,20 @@ class Frontend extends TextScanner {
 
     async updateOptions() {
         this.setOptions(await apiOptionsGet(this.getOptionsContext()));
+
+        const ignoreNodes = ['.scan-disable', '.scan-disable *'];
+        if (!this.options.scanning.enableOnPopupExpressions) {
+            ignoreNodes.push('.source-text', '.source-text *');
+        }
+        this.ignoreNodes = ignoreNodes.join(',');
+
         await this.popup.setOptions(this.options);
+
         this._updateContentScale();
+
+        if (this.textSourceCurrent !== null && this.causeCurrent !== null) {
+            await this.onSearchSource(this.textSourceCurrent, this.causeCurrent);
+        }
     }
 
     async onSearchSource(textSource, cause) {
@@ -241,6 +259,20 @@ class Frontend extends TextScanner {
         this._updatePopupPosition();
     }
 
+    _broadcastRootPopupInformation() {
+        if (!this.popup.isProxy() && this.popup.depth === 0) {
+            apiForward('rootPopupInformation', {popupId: this.popup.id, frameId: this.popup.frameId});
+        }
+    }
+
+    _broadcastDocumentInformation(uniqueId) {
+        apiForward('documentInformationBroadcast', {
+            uniqueId,
+            frameId: this.popup.frameId,
+            title: document.title
+        });
+    }
+
     async _updatePopupPosition() {
         const textSource = this.getCurrentTextSource();
         if (textSource !== null && await this.popup.isVisible()) {
diff --git a/ext/fg/js/popup-nested.js b/ext/fg/js/popup-nested.js
index 06f8fc4b..39d91fd8 100644
--- a/ext/fg/js/popup-nested.js
+++ b/ext/fg/js/popup-nested.js
@@ -36,12 +36,7 @@ async function popupNestedInitialize(id, depth, parentFrameId, url) {
         return;
     }
 
-    const ignoreNodes = ['.scan-disable', '.scan-disable *'];
-    if (!options.scanning.enableOnPopupExpressions) {
-        ignoreNodes.push('.source-text', '.source-text *');
-    }
-
-    window.frontendInitializationData = {id, depth, parentFrameId, ignoreNodes, url, proxy: true};
+    window.frontendInitializationData = {id, depth, parentFrameId, url, proxy: true};
 
     const scriptSrcs = [
         '/mixed/js/text-scanner.js',
diff --git a/ext/fg/js/popup-proxy-host.js b/ext/fg/js/popup-proxy-host.js
index 793d3949..4b136e41 100644
--- a/ext/fg/js/popup-proxy-host.js
+++ b/ext/fg/js/popup-proxy-host.js
@@ -25,19 +25,18 @@
 class PopupProxyHost {
     constructor() {
         this._popups = new Map();
-        this._nextId = 0;
         this._apiReceiver = null;
-        this._frameIdPromise = null;
+        this._frameId = null;
     }
 
     // Public functions
 
     async prepare() {
-        this._frameIdPromise = apiFrameInformationGet();
-        const {frameId} = await this._frameIdPromise;
+        const {frameId} = await apiFrameInformationGet();
         if (typeof frameId !== 'number') { return; }
+        this._frameId = frameId;
 
-        this._apiReceiver = new FrontendApiReceiver(`popup-proxy-host#${frameId}`, new Map([
+        this._apiReceiver = new FrontendApiReceiver(`popup-proxy-host#${this._frameId}`, new Map([
             ['getOrCreatePopup', this._onApiGetOrCreatePopup.bind(this)],
             ['setOptions', this._onApiSetOptions.bind(this)],
             ['hide', this._onApiHide.bind(this)],
@@ -76,7 +75,7 @@ class PopupProxyHost {
 
         // New unique id
         if (id === null) {
-            id = this._nextId++;
+            id = yomichan.generateId(16);
         }
 
         // Create new popup
@@ -88,7 +87,7 @@ class PopupProxyHost {
         } else if (depth === null) {
             depth = 0;
         }
-        const popup = new Popup(id, depth, this._frameIdPromise);
+        const popup = new Popup(id, depth, this._frameId);
         if (parent !== null) {
             popup.setParent(parent);
         }
@@ -96,7 +95,7 @@ class PopupProxyHost {
         return popup;
     }
 
-    // Message handlers
+    // API message handlers
 
     async _onApiGetOrCreatePopup({id, parentId}) {
         const popup = this.getOrCreatePopup(id, parentId);
diff --git a/ext/fg/js/popup-proxy.js b/ext/fg/js/popup-proxy.js
index f7cef214..966198a9 100644
--- a/ext/fg/js/popup-proxy.js
+++ b/ext/fg/js/popup-proxy.js
@@ -21,18 +21,26 @@
  */
 
 class PopupProxy {
-    constructor(id, depth, parentId, parentFrameId, url) {
+    constructor(id, depth, parentId, parentFrameId, url, getFrameOffset=null) {
         this._parentId = parentId;
         this._parentFrameId = parentFrameId;
         this._id = id;
-        this._idPromise = null;
         this._depth = depth;
         this._url = url;
         this._apiSender = new FrontendApiSender();
+        this._getFrameOffset = getFrameOffset;
+
+        this._frameOffset = null;
+        this._frameOffsetPromise = null;
+        this._frameOffsetUpdatedAt = null;
     }
 
     // Public properties
 
+    get id() {
+        return this._id;
+    }
+
     get parent() {
         return null;
     }
@@ -47,92 +55,106 @@ class PopupProxy {
 
     // Public functions
 
+    async prepare() {
+        const {id} = await this._invokeHostApi('getOrCreatePopup', {id: this._id, parentId: this._parentId});
+        this._id = id;
+    }
+
     isProxy() {
         return true;
     }
 
     async setOptions(options) {
-        const id = await this._getPopupId();
-        return await this._invokeHostApi('setOptions', {id, options});
+        return await this._invokeHostApi('setOptions', {id: this._id, options});
     }
 
     hide(changeFocus) {
-        if (this._id === null) {
-            return;
-        }
         this._invokeHostApi('hide', {id: this._id, changeFocus});
     }
 
     async isVisible() {
-        const id = await this._getPopupId();
-        return await this._invokeHostApi('isVisible', {id});
+        return await this._invokeHostApi('isVisible', {id: this._id});
     }
 
     setVisibleOverride(visible) {
-        if (this._id === null) {
-            return;
-        }
         this._invokeHostApi('setVisibleOverride', {id: this._id, visible});
     }
 
     async containsPoint(x, y) {
-        if (this._id === null) {
-            return false;
+        if (this._getFrameOffset !== null) {
+            await this._updateFrameOffset();
+            [x, y] = this._applyFrameOffset(x, y);
         }
         return await this._invokeHostApi('containsPoint', {id: this._id, x, y});
     }
 
     async showContent(elementRect, writingMode, type=null, details=null) {
-        const id = await this._getPopupId();
-        elementRect = PopupProxy._convertDOMRectToJson(elementRect);
-        return await this._invokeHostApi('showContent', {id, elementRect, writingMode, type, details});
+        let {x, y, width, height} = elementRect;
+        if (this._getFrameOffset !== null) {
+            await this._updateFrameOffset();
+            [x, y] = this._applyFrameOffset(x, y);
+        }
+        elementRect = {x, y, width, height};
+        return await this._invokeHostApi('showContent', {id: this._id, elementRect, writingMode, type, details});
     }
 
     async setCustomCss(css) {
-        const id = await this._getPopupId();
-        return await this._invokeHostApi('setCustomCss', {id, css});
+        return await this._invokeHostApi('setCustomCss', {id: this._id, css});
     }
 
     clearAutoPlayTimer() {
-        if (this._id === null) {
-            return;
-        }
         this._invokeHostApi('clearAutoPlayTimer', {id: this._id});
     }
 
     async setContentScale(scale) {
-        const id = await this._getPopupId();
-        this._invokeHostApi('setContentScale', {id, scale});
+        this._invokeHostApi('setContentScale', {id: this._id, scale});
     }
 
     // Private
 
-    _getPopupId() {
-        if (this._idPromise === null) {
-            this._idPromise = this._getPopupIdAsync();
+    _invokeHostApi(action, params={}) {
+        if (typeof this._parentFrameId !== 'number') {
+            return Promise.reject(new Error('Invalid frame'));
         }
-        return this._idPromise;
+        return this._apiSender.invoke(action, params, `popup-proxy-host#${this._parentFrameId}`);
     }
 
-    async _getPopupIdAsync() {
-        const {id} = await this._invokeHostApi('getOrCreatePopup', {id: this._id, parentId: this._parentId});
-        this._id = id;
-        return id;
+    async _updateFrameOffset() {
+        const now = Date.now();
+        const firstRun = this._frameOffsetUpdatedAt === null;
+        const expired = firstRun || this._frameOffsetUpdatedAt < now - PopupProxy._frameOffsetExpireTimeout;
+        if (this._frameOffsetPromise === null && !expired) { return; }
+
+        if (this._frameOffsetPromise !== null) {
+            if (firstRun) {
+                await this._frameOffsetPromise;
+            }
+            return;
+        }
+
+        const promise = this._updateFrameOffsetInner(now);
+        if (firstRun) {
+            await promise;
+        }
     }
 
-    _invokeHostApi(action, params={}) {
-        if (typeof this._parentFrameId !== 'number') {
-            return Promise.reject(new Error('Invalid frame'));
+    async _updateFrameOffsetInner(now) {
+        this._frameOffsetPromise = this._getFrameOffset();
+        try {
+            const offset = await this._frameOffsetPromise;
+            this._frameOffset = offset !== null ? offset : [0, 0];
+            this._frameOffsetUpdatedAt = now;
+        } catch (e) {
+            logError(e);
+        } finally {
+            this._frameOffsetPromise = null;
         }
-        return this._apiSender.invoke(action, params, `popup-proxy-host#${this._parentFrameId}`);
     }
 
-    static _convertDOMRectToJson(domRect) {
-        return {
-            x: domRect.x,
-            y: domRect.y,
-            width: domRect.width,
-            height: domRect.height
-        };
+    _applyFrameOffset(x, y) {
+        const [offsetX, offsetY] = this._frameOffset;
+        return [x + offsetX, y + offsetY];
     }
 }
+
+PopupProxy._frameOffsetExpireTimeout = 1000;
diff --git a/ext/fg/js/popup.js b/ext/fg/js/popup.js
index d752812e..60dc16dd 100644
--- a/ext/fg/js/popup.js
+++ b/ext/fg/js/popup.js
@@ -22,11 +22,10 @@
  */
 
 class Popup {
-    constructor(id, depth, frameIdPromise) {
+    constructor(id, depth, frameId) {
         this._id = id;
         this._depth = depth;
-        this._frameIdPromise = frameIdPromise;
-        this._frameId = null;
+        this._frameId = frameId;
         this._parent = null;
         this._child = null;
         this._childrenSupported = true;
@@ -69,6 +68,10 @@ class Popup {
         return this._depth;
     }
 
+    get frameId() {
+        return this._frameId;
+    }
+
     get url() {
         return window.location.href;
     }
@@ -193,43 +196,42 @@ class Popup {
     }
 
     async _createInjectPromise() {
-        try {
-            const {frameId} = await this._frameIdPromise;
-            if (typeof frameId === 'number') {
-                this._frameId = frameId;
-            }
-        } catch (e) {
-            // NOP
-        }
-
         if (this._messageToken === null) {
             this._messageToken = await apiGetMessageToken();
         }
 
-        return new Promise((resolve) => {
-            const parentFrameId = (typeof this._frameId === 'number' ? this._frameId : null);
-            this._container.setAttribute('src', chrome.runtime.getURL('/fg/float.html'));
-            this._container.addEventListener('load', () => {
-                const uniqueId = yomichan.generateId(32);
-                Popup._listenForDisplayPrepareCompleted(uniqueId, resolve);
-
-                this._invokeApi('prepare', {
-                    options: this._options,
-                    popupInfo: {
-                        id: this._id,
-                        depth: this._depth,
-                        parentFrameId
-                    },
-                    url: this.url,
-                    childrenSupported: this._childrenSupported,
-                    scale: this._contentScale,
-                    uniqueId
-                });
+        const popupPreparedPromise = yomichan.getTemporaryListenerResult(
+            chrome.runtime.onMessage,
+            ({action, params}, {resolve}) => {
+                if (
+                    action === 'popupPrepareCompleted' &&
+                    isObject(params) &&
+                    params.targetPopupId === this._id
+                ) {
+                    resolve();
+                }
+            }
+        );
+
+        const parentFrameId = (typeof this._frameId === 'number' ? this._frameId : null);
+        this._container.setAttribute('src', chrome.runtime.getURL('/fg/float.html'));
+        this._container.addEventListener('load', () => {
+            this._invokeApi('prepare', {
+                popupInfo: {
+                    id: this._id,
+                    depth: this._depth,
+                    parentFrameId
+                },
+                url: this.url,
+                childrenSupported: this._childrenSupported,
+                scale: this._contentScale
             });
-            this._observeFullscreen(true);
-            this._onFullscreenChanged();
-            this._injectStyles();
         });
+        this._observeFullscreen(true);
+        this._onFullscreenChanged();
+        this._injectStyles();
+
+        return popupPreparedPromise;
     }
 
     async _injectStyles() {
@@ -374,23 +376,6 @@ class Popup {
         );
     }
 
-    static _listenForDisplayPrepareCompleted(uniqueId, resolve) {
-        const runtimeMessageCallback = ({action, params}, sender, callback) => {
-            if (
-                action === 'popupPrepareCompleted' &&
-                typeof params === 'object' &&
-                params !== null &&
-                params.uniqueId === uniqueId
-            ) {
-                chrome.runtime.onMessage.removeListener(runtimeMessageCallback);
-                callback();
-                resolve();
-                return false;
-            }
-        };
-        chrome.runtime.onMessage.addListener(runtimeMessageCallback);
-    }
-
     static _getPositionForHorizontalText(elementRect, width, height, viewport, offsetScale, optionsGeneral) {
         const preferBelow = (optionsGeneral.popupHorizontalTextPosition === 'below');
         const horizontalOffset = optionsGeneral.popupHorizontalOffset * offsetScale;
diff --git a/ext/manifest.json b/ext/manifest.json
index 2a602e3b..3a75beb4 100644
--- a/ext/manifest.json
+++ b/ext/manifest.json
@@ -1,7 +1,7 @@
 {
     "manifest_version": 2,
     "name": "Yomichan (testing)",
-    "version": "20.3.14.0",
+    "version": "20.4.10.0",
 
     "description": "Japanese dictionary with Anki integration (testing)",
     "icons": {"16": "mixed/img/icon16.png", "48": "mixed/img/icon48.png", "128": "mixed/img/icon128.png"},
@@ -23,9 +23,12 @@
             "mixed/js/api.js",
             "mixed/js/text-scanner.js",
             "fg/js/document.js",
+            "fg/js/frontend-api-sender.js",
             "fg/js/frontend-api-receiver.js",
             "fg/js/popup.js",
             "fg/js/source.js",
+            "fg/js/frame-offset-forwarder.js",
+            "fg/js/popup-proxy.js",
             "fg/js/popup-proxy-host.js",
             "fg/js/frontend.js",
             "fg/js/frontend-initialize.js"
diff --git a/ext/mixed/css/display-dark.css b/ext/mixed/css/display-dark.css
index c9cd9f90..550dff3e 100644
--- a/ext/mixed/css/display-dark.css
+++ b/ext/mixed/css/display-dark.css
@@ -19,6 +19,8 @@
 
 body { background-color: #1e1e1e; color: #d4d4d4; }
 
+h2 { border-bottom-color: #2f2f2f; }
+
 .navigation-header {
     background-color: #1e1e1e;
     border-bottom-color: #2f2f2f;
@@ -39,6 +41,7 @@ body { background-color: #1e1e1e; color: #d4d4d4; }
 .tag[data-category=frequency]    { background-color: #489148; }
 .tag[data-category=partOfSpeech] { background-color: #565656; }
 .tag[data-category=search]       { background-color: #69696e; }
+.tag[data-category=pitch-accent-dictionary] { background-color: #6640be; }
 
 .term-reasons { color: #888888; }
 
@@ -57,12 +60,15 @@ body { background-color: #1e1e1e; color: #d4d4d4; }
     color: #666666;
 }
 
-.term-definition-container,
-.kanji-glossary-container {
+.term-definition-list,
+.term-pitch-accent-group-list,
+.term-pitch-accent-disambiguation-list,
+.kanji-glossary-list {
     color: #888888;
 }
 
 .term-glossary,
+.term-pitch-accent,
 .kanji-glossary {
     color: #d4d4d4;
 }
@@ -72,3 +78,20 @@ body { background-color: #1e1e1e; color: #d4d4d4; }
     background-color: #d4d4d4;
     color: #1e1e1e;
 }
+
+.term-pitch-accent-container { border-bottom-color: #2f2f2f; }
+
+.term-pitch-accent-character:before { border-color: #ffffff; }
+
+.term-pitch-accent-graph-line,
+.term-pitch-accent-graph-line-tail,
+#term-pitch-accent-graph-dot,
+#term-pitch-accent-graph-dot-downstep,
+#term-pitch-accent-graph-triangle {
+    stroke: #ffffff;
+}
+
+#term-pitch-accent-graph-dot,
+#term-pitch-accent-graph-dot-downstep>circle:last-of-type {
+    fill: #ffffff;
+}
diff --git a/ext/mixed/css/display-default.css b/ext/mixed/css/display-default.css
index 6eee43c4..487b8cb8 100644
--- a/ext/mixed/css/display-default.css
+++ b/ext/mixed/css/display-default.css
@@ -19,6 +19,8 @@
 
 body { background-color: #ffffff; color: #333333; }
 
+h2 { border-bottom-color: #eeeeee; }
+
 .navigation-header {
     background-color: #ffffff;
     border-bottom-color: #eeeeee;
@@ -39,6 +41,7 @@ body { background-color: #ffffff; color: #333333; }
 .tag[data-category=frequency]    { background-color: #5cb85c; }
 .tag[data-category=partOfSpeech] { background-color: #565656; }
 .tag[data-category=search]       { background-color: #8a8a91; }
+.tag[data-category=pitch-accent-dictionary] { background-color: #6640be; }
 
 .term-reasons { color: #777777; }
 
@@ -57,12 +60,15 @@ body { background-color: #ffffff; color: #333333; }
     color: #999999;
 }
 
-.term-definition-container,
-.kanji-glossary-container {
+.term-definition-list,
+.term-pitch-accent-group-list,
+.term-pitch-accent-disambiguation-list,
+.kanji-glossary-list {
     color: #777777;
 }
 
 .term-glossary,
+.term-pitch-accent,
 .kanji-glossary {
     color: #000000;
 }
@@ -72,3 +78,20 @@ body { background-color: #ffffff; color: #333333; }
     background-color: #333333;
     color: #ffffff;
 }
+
+.term-pitch-accent-container { border-bottom-color: #eeeeee; }
+
+.term-pitch-accent-character:before { border-color: #000000; }
+
+.term-pitch-accent-graph-line,
+.term-pitch-accent-graph-line-tail,
+#term-pitch-accent-graph-dot,
+#term-pitch-accent-graph-dot-downstep,
+#term-pitch-accent-graph-triangle {
+    stroke: #000000;
+}
+
+#term-pitch-accent-graph-dot,
+#term-pitch-accent-graph-dot-downstep>circle:last-of-type {
+    fill: #000000;
+}
diff --git a/ext/mixed/css/display.css b/ext/mixed/css/display.css
index 688a357c..a4432016 100644
--- a/ext/mixed/css/display.css
+++ b/ext/mixed/css/display.css
@@ -65,6 +65,14 @@ ol, ul {
     height: 2.28571428em; /* 14px => 32px */
 }
 
+h2 {
+    font-size: 1.25em;
+    font-weight: normal;
+    margin: 0.25em 0 0;
+    border-bottom-width: 0.05714285714285714em; /* 14px * 1.25em => 1px */
+    border-bottom-style: solid;
+}
+
 /*
  * Navigation
  */
@@ -302,6 +310,7 @@ button.action-button {
     width: 0;
     height: 0;
     visibility: hidden;
+    z-index: 1;
 }
 
 .term-expression-list[data-multi=true] .term-expression:hover .term-expression-details {
@@ -422,6 +431,187 @@ button.action-button {
     display: inline;
 }
 
+.term-entry-body[data-section-count="0"] .term-entry-body-section-header,
+.term-entry-body[data-section-count="1"] .term-entry-body-section-header {
+    display: none;
+}
+
+
+/*
+ * Pitch accent styles
+ */
+
+.entry[data-pitch-accent-count='0'] .term-pitch-accent-container {
+    display: none;
+}
+
+.term-pitch-accent-container {
+    border-bottom-width: 0.05714285714285714em; /* 14px * 1.25em => 1px */
+    border-bottom-style: solid;
+    padding-bottom: 0.25em;
+    margin-bottom: 0.25em;
+}
+
+.term-pitch-accent-group-list {
+    margin: 0;
+    padding: 0;
+    list-style-type: none;
+}
+
+.term-pitch-accent-group-list:not([data-count="0"]):not([data-count="1"]) {
+    padding-left: 1.4em;
+    list-style-type: decimal;
+}
+
+.term-pitch-accent-list {
+    margin: 0;
+    padding: 0;
+    list-style-type: none;
+    display: inline;
+}
+
+.term-pitch-accent-list:not([data-count="0"]):not([data-count="1"]) {
+    padding-left: 1.4em;
+    list-style-type: circle;
+    display: block;
+}
+
+.term-pitch-accent {
+    display: inline;
+    line-height: 1.5em;
+}
+
+.term-pitch-accent-list:not([data-count="0"]):not([data-count="1"])>.term-pitch-accent {
+    display: list-item;
+}
+
+.term-pitch-accent-group-tag-list {
+    margin-right: 0.375em;
+}
+
+.term-pitch-accent-disambiguation-list {
+    padding-right: 0.25em;
+}
+
+.term-pitch-accent-disambiguation-list:before {
+    content: "(";
+}
+
+.term-pitch-accent-disambiguation-list:after {
+    content: " only)";
+}
+
+.term-pitch-accent-disambiguation+.term-pitch-accent-disambiguation:before {
+    content: ", ";
+}
+
+.term-pitch-accent-disambiguation-list[data-count="0"],
+:root[data-show-pitch-accent-downstep-notation=true] .term-pitch-accent-disambiguation-list[data-expression-count="0"],
+:root[data-show-pitch-accent-downstep-notation=true] .term-pitch-accent-disambiguation[data-type=reading] {
+    display: none;
+}
+
+.term-pitch-accent-tag-list:not([data-count="0"]) {
+    margin-right: 0.375em;
+}
+
+.term-special-tags>.pitches {
+    display: inline;
+}
+
+.term-pitch-accent-character {
+    display: inline-block;
+    position: relative;
+}
+.term-pitch-accent-character[data-pitch='high']:before {
+    content: "";
+    display: block;
+    user-select: none;
+    pointer-events: none;
+    position: absolute;
+    top: 0.1em;
+    left: 0;
+    right: 0;
+    height: 0;
+    border-top-width: 0.1em;
+    border-top-style: solid;
+}
+.term-pitch-accent-character[data-pitch='high'][data-pitch-next='low']:before {
+    right: -0.1em;
+    height: 0.4em;
+    border-right-width: 0.1em;
+    border-right-style: solid;
+}
+.term-pitch-accent-character[data-pitch='high'][data-pitch-next='low'] {
+    padding-right: 0.1em;
+    margin-right: 0.1em;
+}
+
+.term-pitch-accent-position:before {
+    content: " [";
+}
+.term-pitch-accent-position:after {
+    content: "]";
+}
+
+.term-pitch-accent-details {
+    display: inline-block;
+    height: 0;
+    padding: 0 0.25em;
+    vertical-align: middle;
+}
+
+
+:root[data-show-pitch-accent-downstep-notation=false] .term-pitch-accent-characters {
+    display: none;
+}
+
+:root[data-show-pitch-accent-position-notation=false] .term-pitch-accent-position {
+    display: none;
+}
+
+:root[data-show-pitch-accent-graph=false] .term-pitch-accent-details {
+    display: none;
+}
+
+
+/*
+ * Pitch accent graph styles
+ */
+
+.term-pitch-accent-graph {
+    display: block;
+    height: 1.5em;
+    transform: translateY(-0.875em);
+}
+.term-pitch-accent-graph-line,
+.term-pitch-accent-graph-line-tail {
+    fill: none;
+    stroke: #000000;
+    stroke-width: 5;
+}
+.term-pitch-accent-graph-line-tail {
+    stroke-dasharray: 5 5;
+}
+#term-pitch-accent-graph-dot {
+    fill: #000000;
+    stroke: #000000;
+    stroke-width: 5;
+}
+#term-pitch-accent-graph-dot-downstep {
+    fill: none;
+    stroke: #000000;
+    stroke-width: 5;
+}
+#term-pitch-accent-graph-dot-downstep>circle:last-of-type {
+    fill: #000000;
+}
+#term-pitch-accent-graph-triangle {
+    fill: none;
+    stroke: #000000;
+    stroke-width: 5;
+}
+
 
 /*
  * Kanji
diff --git a/ext/mixed/display-templates.html b/ext/mixed/display-templates.html
index 7ae51a62..b8d52d15 100644
--- a/ext/mixed/display-templates.html
+++ b/ext/mixed/display-templates.html
@@ -17,7 +17,10 @@
         </div>
         <div class="term-special-tags"><div class="frequencies tag-list"></div></div>
     </div>
-    <div class="term-definition-container"><ol class="term-definition-list"></ol></div>
+    <div class="term-entry-body">
+        <div class="term-entry-body-section term-pitch-accent-container"><ol class="term-entry-body-section-content term-pitch-accent-group-list"></ol></div>
+        <div class="term-entry-body-section term-definition-container"><ol class="term-entry-body-section-content term-definition-list"></ol></div>
+    </div>
     <pre class="debug-info"></pre>
 </div></template>
 <template id="term-expression-template"><div class="term-expression"><span class="term-expression-text source-text"></span><div class="term-expression-details">
@@ -34,6 +37,18 @@
 <template id="term-glossary-item-template"><li class="term-glossary-item"><span class="term-glossary-separator"> </span><span class="term-glossary"></span></li></template>
 <template id="term-reason-template"><span class="term-reason"></span><span class="term-reason-separator"> </span></template>
 
+<template id="term-pitch-accent-static-template"><svg xmlns="http://www.w3.org/2000/svg" style="display: none;">
+    <defs>
+        <g id="term-pitch-accent-graph-dot"><circle cx="0" cy="0" r="15" /></g>
+        <g id="term-pitch-accent-graph-dot-downstep"><circle cx="0" cy="0" r="15" /><circle cx="0" cy="0" r="5" /></g>
+        <g id="term-pitch-accent-graph-triangle"><path d="M0 13 L15 -13 L-15 -13 Z" /></g>
+    </defs>
+</svg></template>
+<template id="term-pitch-accent-group-template"><li class="term-pitch-accent-group"><span class="term-pitch-accent-group-tag-list tag-list"></span><ul class="term-pitch-accent-list"></ul></li></template>
+<template id="term-pitch-accent-disambiguation-template"><span class="term-pitch-accent-disambiguation"></span></template>
+<template id="term-pitch-accent-template"><li class="term-pitch-accent"><span class="term-pitch-accent-tag-list tag-list"></span><span class="term-pitch-accent-disambiguation-list"></span><span class="term-pitch-accent-characters"></span><span class="term-pitch-accent-position"></span><span class="term-pitch-accent-details"><svg class="term-pitch-accent-graph" xmlns="http://www.w3.org/2000/svg"><path class="term-pitch-accent-graph-line" /><path class="term-pitch-accent-graph-line-tail" /></svg></span></li></template>
+<template id="term-pitch-accent-character-template"><span class="term-pitch-accent-character"><span class="term-pitch-accent-character-inner"></span></span></template>
+
 <template id="kanji-entry-template"><div class="entry" data-type="kanji">
     <div class="entry-header1">
         <div class="entry-header2">
diff --git a/ext/mixed/js/api.js b/ext/mixed/js/api.js
index 0ab07039..feec94df 100644
--- a/ext/mixed/js/api.js
+++ b/ext/mixed/js/api.js
@@ -53,12 +53,12 @@ function apiKanjiFind(text, optionsContext) {
     return _apiInvoke('kanjiFind', {text, optionsContext});
 }
 
-function apiDefinitionAdd(definition, mode, context, optionsContext) {
-    return _apiInvoke('definitionAdd', {definition, mode, context, optionsContext});
+function apiDefinitionAdd(definition, mode, context, details, optionsContext) {
+    return _apiInvoke('definitionAdd', {definition, mode, context, details, optionsContext});
 }
 
-function apiDefinitionsAddable(definitions, modes, optionsContext) {
-    return _apiInvoke('definitionsAddable', {definitions, modes, optionsContext});
+function apiDefinitionsAddable(definitions, modes, context, optionsContext) {
+    return _apiInvoke('definitionsAddable', {definitions, modes, context, optionsContext});
 }
 
 function apiNoteView(noteId) {
diff --git a/ext/mixed/js/core.js b/ext/mixed/js/core.js
index 0d50e915..db7fc69b 100644
--- a/ext/mixed/js/core.js
+++ b/ext/mixed/js/core.js
@@ -132,6 +132,30 @@ function parseUrl(url) {
     return {baseUrl, queryParams};
 }
 
+function areSetsEqual(set1, set2) {
+    if (set1.size !== set2.size) {
+        return false;
+    }
+
+    for (const value of set1) {
+        if (!set2.has(value)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+function getSetIntersection(set1, set2) {
+    const result = [];
+    for (const value of set1) {
+        if (set2.has(value)) {
+            result.push(value);
+        }
+    }
+    return result;
+}
+
 
 /*
  * Async utilities
@@ -254,11 +278,16 @@ const yomichan = (() => {
         constructor() {
             super();
 
-            this._isBackendPreparedResolve = null;
-            this._isBackendPreparedPromise = new Promise((resolve) => (this._isBackendPreparedResolve = resolve));
+            this._isBackendPreparedPromise = this.getTemporaryListenerResult(
+                chrome.runtime.onMessage,
+                ({action}, {resolve}) => {
+                    if (action === 'backendPrepared') {
+                        resolve();
+                    }
+                }
+            );
 
             this._messageHandlers = new Map([
-                ['backendPrepared', this._onBackendPrepared.bind(this)],
                 ['getUrl', this._onMessageGetUrl.bind(this)],
                 ['optionsUpdated', this._onMessageOptionsUpdated.bind(this)],
                 ['zoomChanged', this._onMessageZoomChanged.bind(this)]
@@ -288,6 +317,42 @@ const yomichan = (() => {
             this.trigger('orphaned', {error});
         }
 
+        getTemporaryListenerResult(eventHandler, userCallback, timeout=null) {
+            if (!(
+                typeof eventHandler.addListener === 'function' &&
+                typeof eventHandler.removeListener === 'function'
+            )) {
+                throw new Error('Event handler type not supported');
+            }
+
+            return new Promise((resolve, reject) => {
+                const runtimeMessageCallback = ({action, params}, sender, sendResponse) => {
+                    let timeoutId = null;
+                    if (timeout !== null) {
+                        timeoutId = window.setTimeout(() => {
+                            timeoutId = null;
+                            eventHandler.removeListener(runtimeMessageCallback);
+                            reject(new Error(`Listener timed out in ${timeout} ms`));
+                        }, timeout);
+                    }
+
+                    const cleanupResolve = (value) => {
+                        if (timeoutId !== null) {
+                            window.clearTimeout(timeoutId);
+                            timeoutId = null;
+                        }
+                        eventHandler.removeListener(runtimeMessageCallback);
+                        sendResponse();
+                        resolve(value);
+                    };
+
+                    userCallback({action, params}, {resolve: cleanupResolve, sender});
+                };
+
+                eventHandler.addListener(runtimeMessageCallback);
+            });
+        }
+
         // Private
 
         _onMessage({action, params}, sender, callback) {
@@ -299,10 +364,6 @@ const yomichan = (() => {
             return false;
         }
 
-        _onBackendPrepared() {
-            this._isBackendPreparedResolve();
-        }
-
         _onMessageGetUrl() {
             return {url: window.location.href};
         }
diff --git a/ext/mixed/js/display-generator.js b/ext/mixed/js/display-generator.js
index 49afc44b..f1122e3d 100644
--- a/ext/mixed/js/display-generator.js
+++ b/ext/mixed/js/display-generator.js
@@ -19,11 +19,13 @@
 /* global
  * TemplateHandler
  * apiGetDisplayTemplatesHtml
+ * jp
  */
 
 class DisplayGenerator {
     constructor() {
         this._templateHandler = null;
+        this._termPitchAccentStaticTemplateIsSetup = false;
     }
 
     async prepare() {
@@ -36,17 +38,33 @@ class DisplayGenerator {
 
         const expressionsContainer = node.querySelector('.term-expression-list');
         const reasonsContainer = node.querySelector('.term-reasons');
+        const pitchesContainer = node.querySelector('.term-pitch-accent-group-list');
         const frequenciesContainer = node.querySelector('.frequencies');
         const definitionsContainer = node.querySelector('.term-definition-list');
         const debugInfoContainer = node.querySelector('.debug-info');
+        const bodyContainer = node.querySelector('.term-entry-body');
+
+        const pitches = DisplayGenerator._getPitchInfos(details);
+        const pitchCount = pitches.reduce((i, v) => i + v[1].length, 0);
 
         const expressionMulti = Array.isArray(details.expressions);
         const definitionMulti = Array.isArray(details.definitions);
+        const expressionCount = expressionMulti ? details.expressions.length : 1;
+        const definitionCount = definitionMulti ? details.definitions.length : 1;
+        const uniqueExpressionCount = Array.isArray(details.expression) ? new Set(details.expression).size : 1;
 
         node.dataset.expressionMulti = `${expressionMulti}`;
         node.dataset.definitionMulti = `${definitionMulti}`;
-        node.dataset.expressionCount = `${expressionMulti ? details.expressions.length : 1}`;
-        node.dataset.definitionCount = `${definitionMulti ? details.definitions.length : 1}`;
+        node.dataset.expressionCount = `${expressionCount}`;
+        node.dataset.definitionCount = `${definitionCount}`;
+        node.dataset.uniqueExpressionCount = `${uniqueExpressionCount}`;
+        node.dataset.pitchAccentDictionaryCount = `${pitches.length}`;
+        node.dataset.pitchAccentCount = `${pitchCount}`;
+
+        bodyContainer.dataset.sectionCount = `${
+            (definitionCount > 0 ? 1 : 0) +
+            (pitches.length > 0 ? 1 : 0)
+        }`;
 
         const termTags = details.termTags;
         let expressions = details.expressions;
@@ -55,6 +73,7 @@ class DisplayGenerator {
         DisplayGenerator._appendMultiple(expressionsContainer, this.createTermExpression.bind(this), expressions, [[details, termTags]]);
         DisplayGenerator._appendMultiple(reasonsContainer, this.createTermReason.bind(this), details.reasons);
         DisplayGenerator._appendMultiple(frequenciesContainer, this.createFrequencyTag.bind(this), details.frequencies);
+        DisplayGenerator._appendMultiple(pitchesContainer, this.createPitches.bind(this), pitches);
         DisplayGenerator._appendMultiple(definitionsContainer, this.createTermDefinitionItem.bind(this), details.definitions, [details]);
 
         if (debugInfoContainer !== null) {
@@ -261,6 +280,133 @@ class DisplayGenerator {
         return node;
     }
 
+    createPitches(details) {
+        if (!this._termPitchAccentStaticTemplateIsSetup) {
+            this._termPitchAccentStaticTemplateIsSetup = true;
+            const t = this._templateHandler.instantiate('term-pitch-accent-static');
+            document.head.appendChild(t);
+        }
+
+        const [dictionary, dictionaryPitches] = details;
+
+        const node = this._templateHandler.instantiate('term-pitch-accent-group');
+        node.dataset.dictionary = dictionary;
+        node.dataset.pitchesMulti = 'true';
+        node.dataset.pitchesCount = `${dictionaryPitches.length}`;
+
+        const tag = this.createTag({notes: '', name: dictionary, category: 'pitch-accent-dictionary'});
+        node.querySelector('.term-pitch-accent-group-tag-list').appendChild(tag);
+
+        const n = node.querySelector('.term-pitch-accent-list');
+        DisplayGenerator._appendMultiple(n, this.createPitch.bind(this), dictionaryPitches);
+
+        return node;
+    }
+
+    createPitch(details) {
+        const {reading, position, tags, exclusiveExpressions, exclusiveReadings} = details;
+        const morae = jp.getKanaMorae(reading);
+
+        const node = this._templateHandler.instantiate('term-pitch-accent');
+
+        node.dataset.pitchAccentPosition = `${position}`;
+        node.dataset.tagCount = `${tags.length}`;
+
+        let n = node.querySelector('.term-pitch-accent-position');
+        n.textContent = `${position}`;
+
+        n = node.querySelector('.term-pitch-accent-tag-list');
+        DisplayGenerator._appendMultiple(n, this.createTag.bind(this), tags);
+
+        n = node.querySelector('.term-pitch-accent-disambiguation-list');
+        this.createPitchAccentDisambiguations(n, exclusiveExpressions, exclusiveReadings);
+
+        n = node.querySelector('.term-pitch-accent-characters');
+        for (let i = 0, ii = morae.length; i < ii; ++i) {
+            const mora = morae[i];
+            const highPitch = jp.isMoraPitchHigh(i, position);
+            const highPitchNext = jp.isMoraPitchHigh(i + 1, position);
+
+            const n1 = this._templateHandler.instantiate('term-pitch-accent-character');
+            const n2 = n1.querySelector('.term-pitch-accent-character-inner');
+
+            n1.dataset.position = `${i}`;
+            n1.dataset.pitch = highPitch ? 'high' : 'low';
+            n1.dataset.pitchNext = highPitchNext ? 'high' : 'low';
+            n2.textContent = mora;
+
+            n.appendChild(n1);
+        }
+
+        if (morae.length > 0) {
+            this.populatePitchGraph(node.querySelector('.term-pitch-accent-graph'), position, morae);
+        }
+
+        return node;
+    }
+
+    createPitchAccentDisambiguations(container, exclusiveExpressions, exclusiveReadings) {
+        const templateName = 'term-pitch-accent-disambiguation';
+        for (const exclusiveExpression of exclusiveExpressions) {
+            const node = this._templateHandler.instantiate(templateName);
+            node.dataset.type = 'expression';
+            node.textContent = exclusiveExpression;
+            container.appendChild(node);
+        }
+
+        for (const exclusiveReading of exclusiveReadings) {
+            const node = this._templateHandler.instantiate(templateName);
+            node.dataset.type = 'reading';
+            node.textContent = exclusiveReading;
+            container.appendChild(node);
+        }
+
+        container.dataset.multi = 'true';
+        container.dataset.count = `${exclusiveExpressions.length + exclusiveReadings.length}`;
+        container.dataset.expressionCount = `${exclusiveExpressions.length}`;
+        container.dataset.readingCount = `${exclusiveReadings.length}`;
+    }
+
+    populatePitchGraph(svg, position, morae) {
+        const svgns = svg.getAttribute('xmlns');
+        const ii = morae.length;
+        svg.setAttribute('viewBox', `0 0 ${50 * (ii + 1)} 100`);
+
+        const pathPoints = [];
+        for (let i = 0; i < ii; ++i) {
+            const highPitch = jp.isMoraPitchHigh(i, position);
+            const highPitchNext = jp.isMoraPitchHigh(i + 1, position);
+            const graphic = (highPitch && !highPitchNext ? '#term-pitch-accent-graph-dot-downstep' : '#term-pitch-accent-graph-dot');
+            const x = `${i * 50 + 25}`;
+            const y = highPitch ? '25' : '75';
+            const use = document.createElementNS(svgns, 'use');
+            use.setAttribute('href', graphic);
+            use.setAttribute('x', x);
+            use.setAttribute('y', y);
+            svg.appendChild(use);
+            pathPoints.push(`${x} ${y}`);
+        }
+
+        let path = svg.querySelector('.term-pitch-accent-graph-line');
+        path.setAttribute('d', `M${pathPoints.join(' L')}`);
+
+        pathPoints.splice(0, ii - 1);
+        {
+            const highPitch = jp.isMoraPitchHigh(ii, position);
+            const x = `${ii * 50 + 25}`;
+            const y = highPitch ? '25' : '75';
+            const use = document.createElementNS(svgns, 'use');
+            use.setAttribute('href', '#term-pitch-accent-graph-triangle');
+            use.setAttribute('x', x);
+            use.setAttribute('y', y);
+            svg.appendChild(use);
+            pathPoints.push(`${x} ${y}`);
+        }
+
+        path = svg.querySelector('.term-pitch-accent-graph-line-tail');
+        path.setAttribute('d', `M${pathPoints.join(' L')}`);
+    }
+
     createFrequencyTag(details) {
         const node = this._templateHandler.instantiate('tag-frequency');
 
@@ -283,7 +429,7 @@ class DisplayGenerator {
     _appendKanjiLinks(container, text) {
         let part = '';
         for (const c of text) {
-            if (DisplayGenerator._isCharacterKanji(c)) {
+            if (jp.isCodePointKanji(c.codePointAt(0))) {
                 if (part.length > 0) {
                     container.appendChild(document.createTextNode(part));
                     part = '';
@@ -300,30 +446,28 @@ class DisplayGenerator {
         }
     }
 
-    static _isCharacterKanji(c) {
-        const code = c.codePointAt(0);
-        return (
-            code >= 0x4e00 && code < 0x9fb0 ||
-            code >= 0x3400 && code < 0x4dc0
-        );
-    }
-
-    static _appendMultiple(container, createItem, detailsArray, fallback=[]) {
+    static _appendMultiple(container, createItem, detailsIterable, fallback=[]) {
         if (container === null) { return 0; }
 
-        const isArray = Array.isArray(detailsArray);
-        if (!isArray) { detailsArray = fallback; }
-
-        container.dataset.multi = `${isArray}`;
-        container.dataset.count = `${detailsArray.length}`;
+        const multi = (
+            detailsIterable !== null &&
+            typeof detailsIterable === 'object' &&
+            typeof detailsIterable[Symbol.iterator] !== 'undefined'
+        );
+        if (!multi) { detailsIterable = fallback; }
 
-        for (const details of detailsArray) {
+        let count = 0;
+        for (const details of detailsIterable) {
             const item = createItem(details);
             if (item === null) { continue; }
             container.appendChild(item);
+            ++count;
         }
 
-        return detailsArray.length;
+        container.dataset.multi = `${multi}`;
+        container.dataset.count = `${count}`;
+
+        return count;
     }
 
     static _appendFurigana(container, segments, addText) {
@@ -349,4 +493,79 @@ class DisplayGenerator {
             container.appendChild(document.createTextNode(parts[i]));
         }
     }
+
+    static _getPitchInfos(definition) {
+        const results = new Map();
+
+        const allExpressions = new Set();
+        const allReadings = new Set();
+        const expressions = definition.expressions;
+        const sources = Array.isArray(expressions) ? expressions : [definition];
+        for (const {pitches: expressionPitches, expression} of sources) {
+            allExpressions.add(expression);
+            for (const {reading, pitches, dictionary} of expressionPitches) {
+                allReadings.add(reading);
+                let dictionaryResults = results.get(dictionary);
+                if (typeof dictionaryResults === 'undefined') {
+                    dictionaryResults = [];
+                    results.set(dictionary, dictionaryResults);
+                }
+
+                for (const {position, tags} of pitches) {
+                    let pitchInfo = DisplayGenerator._findExistingPitchInfo(reading, position, tags, dictionaryResults);
+                    if (pitchInfo === null) {
+                        pitchInfo = {expressions: new Set(), reading, position, tags};
+                        dictionaryResults.push(pitchInfo);
+                    }
+                    pitchInfo.expressions.add(expression);
+                }
+            }
+        }
+
+        for (const dictionaryResults of results.values()) {
+            for (const result of dictionaryResults) {
+                const exclusiveExpressions = [];
+                const exclusiveReadings = [];
+                const resultExpressions = result.expressions;
+                if (!areSetsEqual(resultExpressions, allExpressions)) {
+                    exclusiveExpressions.push(...getSetIntersection(resultExpressions, allExpressions));
+                }
+                if (allReadings.size > 1) {
+                    exclusiveReadings.push(result.reading);
+                }
+                result.exclusiveExpressions = exclusiveExpressions;
+                result.exclusiveReadings = exclusiveReadings;
+            }
+        }
+
+        return [...results.entries()];
+    }
+
+    static _findExistingPitchInfo(reading, position, tags, pitchInfoList) {
+        for (const pitchInfo of pitchInfoList) {
+            if (
+                pitchInfo.reading === reading &&
+                pitchInfo.position === position &&
+                DisplayGenerator._areTagListsEqual(pitchInfo.tags, tags)
+            ) {
+                return pitchInfo;
+            }
+        }
+        return null;
+    }
+
+    static _areTagListsEqual(tagList1, tagList2) {
+        const ii = tagList1.length;
+        if (tagList2.length !== ii) { return false; }
+
+        for (let i = 0; i < ii; ++i) {
+            const tag1 = tagList1[i];
+            const tag2 = tagList2[i];
+            if (tag1.name !== tag2.name || tag1.dictionary !== tag2.dictionary) {
+                return false;
+            }
+        }
+
+        return true;
+    }
 }
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index 515e28a7..2f456c3e 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -40,6 +40,7 @@ class Display {
         this.spinner = spinner;
         this.container = container;
         this.definitions = [];
+        this.optionsContext = null;
         this.options = null;
         this.context = null;
         this.index = 0;
@@ -165,12 +166,11 @@ class Display {
         this.setInteractive(true);
     }
 
-    async prepare(options=null) {
+    async prepare() {
         await yomichan.prepare();
-        const displayGeneratorPromise = this.displayGenerator.prepare();
-        const updateOptionsPromise = this.updateOptions(options);
-        await Promise.all([displayGeneratorPromise, updateOptionsPromise]);
-        yomichan.on('optionsUpdated', () => this.updateOptions(null));
+        await this.displayGenerator.prepare();
+        await this.updateOptions();
+        yomichan.on('optionsUpdated', () => this.updateOptions());
     }
 
     onError(_error) {
@@ -369,11 +369,11 @@ class Display {
     }
 
     getOptionsContext() {
-        throw new Error('Override me');
+        return this.optionsContext;
     }
 
-    async updateOptions(options) {
-        this.options = options ? options : await apiOptionsGet(this.getOptionsContext());
+    async updateOptions() {
+        this.options = await apiOptionsGet(this.getOptionsContext());
         this.updateDocumentOptions(this.options);
         this.updateTheme(this.options.general.popupTheme);
         this.setCustomCss(this.options.general.customPopupCss);
@@ -385,6 +385,9 @@ class Display {
         data.audioEnabled = `${options.audio.enabled}`;
         data.compactGlossaries = `${options.general.compactGlossaries}`;
         data.enableSearchTags = `${options.scanning.enableSearchTags}`;
+        data.showPitchAccentDownstepNotation = `${options.general.showPitchAccentDownstepNotation}`;
+        data.showPitchAccentPositionNotation = `${options.general.showPitchAccentPositionNotation}`;
+        data.showPitchAccentGraph = `${options.general.showPitchAccentGraph}`;
         data.debug = `${options.general.debugInfo}`;
     }
 
@@ -749,15 +752,16 @@ class Display {
         try {
             this.setSpinnerVisible(true);
 
-            const context = {};
+            const details = {};
             if (this.noteUsesScreenshot(mode)) {
                 const screenshot = await this.getScreenshot();
                 if (screenshot) {
-                    context.screenshot = screenshot;
+                    details.screenshot = screenshot;
                 }
             }
 
-            const noteId = await apiDefinitionAdd(definition, mode, context, this.getOptionsContext());
+            const context = await this._getNoteContext();
+            const noteId = await apiDefinitionAdd(definition, mode, context, details, this.getOptionsContext());
             if (noteId) {
                 const index = this.definitions.indexOf(definition);
                 const adderButton = this.adderButtonFind(index, mode);
@@ -905,12 +909,17 @@ class Display {
 
     async getDefinitionsAddable(definitions, modes) {
         try {
-            return await apiDefinitionsAddable(definitions, modes, this.getOptionsContext());
+            const context = await this._getNoteContext();
+            return await apiDefinitionsAddable(definitions, modes, context, this.getOptionsContext());
         } catch (e) {
             return [];
         }
     }
 
+    async getDocumentTitle() {
+        return document.title;
+    }
+
     static indexOf(nodeList, node) {
         for (let i = 0, ii = nodeList.length; i < ii; ++i) {
             if (nodeList[i] === node) {
@@ -931,6 +940,15 @@ class Display {
         return (typeof key === 'string' ? (key.length === 1 ? key.toUpperCase() : key) : '');
     }
 
+    async _getNoteContext() {
+        const documentTitle = await this.getDocumentTitle();
+        return {
+            document: {
+                title: documentTitle
+            }
+        };
+    }
+
     async _getAudioUri(definition, source) {
         const optionsContext = this.getOptionsContext();
         return await apiAudioGetUri(definition, source, optionsContext);
diff --git a/ext/mixed/js/japanese.js b/ext/mixed/js/japanese.js
new file mode 100644
index 00000000..e6b9a8a0
--- /dev/null
+++ b/ext/mixed/js/japanese.js
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const jp = (() => {
+    const HIRAGANA_RANGE = [0x3040, 0x309f];
+    const KATAKANA_RANGE = [0x30a0, 0x30ff];
+    const KANA_RANGES = [HIRAGANA_RANGE, KATAKANA_RANGE];
+
+    const CJK_UNIFIED_IDEOGRAPHS_RANGE = [0x4e00, 0x9fff];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A_RANGE = [0x3400, 0x4dbf];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B_RANGE = [0x20000, 0x2a6df];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_C_RANGE = [0x2a700, 0x2b73f];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_D_RANGE = [0x2b740, 0x2b81f];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E_RANGE = [0x2b820, 0x2ceaf];
+    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_F_RANGE = [0x2ceb0, 0x2ebef];
+    const CJK_COMPATIBILITY_IDEOGRAPHS_SUPPLEMENT_RANGE = [0x2f800, 0x2fa1f];
+    const CJK_UNIFIED_IDEOGRAPHS_RANGES = [
+        CJK_UNIFIED_IDEOGRAPHS_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_C_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_D_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E_RANGE,
+        CJK_UNIFIED_IDEOGRAPHS_EXTENSION_F_RANGE,
+        CJK_COMPATIBILITY_IDEOGRAPHS_SUPPLEMENT_RANGE
+    ];
+
+    // Japanese character ranges, roughly ordered in order of expected frequency
+    const JAPANESE_RANGES = [
+        HIRAGANA_RANGE,
+        KATAKANA_RANGE,
+
+        ...CJK_UNIFIED_IDEOGRAPHS_RANGES,
+
+        [0xff66, 0xff9f], // Halfwidth katakana
+
+        [0x30fb, 0x30fc], // Katakana punctuation
+        [0xff61, 0xff65], // Kana punctuation
+        [0x3000, 0x303f], // CJK punctuation
+
+        [0xff10, 0xff19], // Fullwidth numbers
+        [0xff21, 0xff3a], // Fullwidth upper case Latin letters
+        [0xff41, 0xff5a], // Fullwidth lower case Latin letters
+
+        [0xff01, 0xff0f], // Fullwidth punctuation 1
+        [0xff1a, 0xff1f], // Fullwidth punctuation 2
+        [0xff3b, 0xff3f], // Fullwidth punctuation 3
+        [0xff5b, 0xff60], // Fullwidth punctuation 4
+        [0xffe0, 0xffee]  // Currency markers
+    ];
+
+    const SMALL_KANA_SET = new Set(Array.from('ぁぃぅぇぉゃゅょゎァィゥェォャュョヮ'));
+
+
+    // Character code testing functions
+
+    function isCodePointKanji(codePoint) {
+        return isCodePointInRanges(codePoint, CJK_UNIFIED_IDEOGRAPHS_RANGES);
+    }
+
+    function isCodePointKana(codePoint) {
+        return isCodePointInRanges(codePoint, KANA_RANGES);
+    }
+
+    function isCodePointJapanese(codePoint) {
+        return isCodePointInRanges(codePoint, JAPANESE_RANGES);
+    }
+
+    function isCodePointInRanges(codePoint, ranges) {
+        for (const [min, max] of ranges) {
+            if (codePoint >= min && codePoint <= max) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+
+    // String testing functions
+
+    function isStringEntirelyKana(str) {
+        if (str.length === 0) { return false; }
+        for (const c of str) {
+            if (!isCodePointKana(c.codePointAt(0))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    function isStringPartiallyJapanese(str) {
+        if (str.length === 0) { return false; }
+        for (const c of str) {
+            if (isCodePointJapanese(c.codePointAt(0))) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+
+    // Mora functions
+
+    function isMoraPitchHigh(moraIndex, pitchAccentPosition) {
+        return pitchAccentPosition === 0 ? (moraIndex > 0) : (moraIndex < pitchAccentPosition);
+    }
+
+    function getKanaMorae(text) {
+        const morae = [];
+        let i;
+        for (const c of text) {
+            if (SMALL_KANA_SET.has(c) && (i = morae.length) > 0) {
+                morae[i - 1] += c;
+            } else {
+                morae.push(c);
+            }
+        }
+        return morae;
+    }
+
+
+    // Exports
+
+    return {
+        isCodePointKanji,
+        isCodePointKana,
+        isCodePointJapanese,
+        isStringEntirelyKana,
+        isStringPartiallyJapanese,
+        isMoraPitchHigh,
+        getKanaMorae
+    };
+})();
diff --git a/ext/mixed/js/object-property-accessor.js b/ext/mixed/js/object-property-accessor.js
new file mode 100644
index 00000000..108afc0d
--- /dev/null
+++ b/ext/mixed/js/object-property-accessor.js
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2016-2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Class used to get and set generic properties of an object by using path strings.
+ */
+class ObjectPropertyAccessor {
+    constructor(target, setter=null) {
+        this._target = target;
+        this._setter = (typeof setter === 'function' ? setter : null);
+    }
+
+    getProperty(pathArray, pathLength) {
+        let target = this._target;
+        const ii = typeof pathLength === 'number' ? Math.min(pathArray.length, pathLength) : pathArray.length;
+        for (let i = 0; i < ii; ++i) {
+            const key = pathArray[i];
+            if (!ObjectPropertyAccessor.hasProperty(target, key)) {
+                throw new Error(`Invalid path: ${ObjectPropertyAccessor.getPathString(pathArray.slice(0, i + 1))}`);
+            }
+            target = target[key];
+        }
+        return target;
+    }
+
+    setProperty(pathArray, value) {
+        if (pathArray.length === 0) {
+            throw new Error('Invalid path');
+        }
+
+        const target = this.getProperty(pathArray, pathArray.length - 1);
+        const key = pathArray[pathArray.length - 1];
+        if (!ObjectPropertyAccessor.isValidPropertyType(target, key)) {
+            throw new Error(`Invalid path: ${ObjectPropertyAccessor.getPathString(pathArray)}`);
+        }
+
+        if (this._setter !== null) {
+            this._setter(target, key, value, pathArray);
+        } else {
+            target[key] = value;
+        }
+    }
+
+    static getPathString(pathArray) {
+        const regexShort = /^[a-zA-Z_][a-zA-Z0-9_]*$/;
+        let pathString = '';
+        let first = true;
+        for (let part of pathArray) {
+            switch (typeof part) {
+                case 'number':
+                    if (Math.floor(part) !== part || part < 0) {
+                        throw new Error('Invalid index');
+                    }
+                    part = `[${part}]`;
+                    break;
+                case 'string':
+                    if (!regexShort.test(part)) {
+                        const escapedPart = part.replace(/["\\]/g, '\\$&');
+                        part = `["${escapedPart}"]`;
+                    } else {
+                        if (!first) {
+                            part = `.${part}`;
+                        }
+                    }
+                    break;
+                default:
+                    throw new Error(`Invalid type: ${typeof part}`);
+            }
+            pathString += part;
+            first = false;
+        }
+        return pathString;
+    }
+
+    static getPathArray(pathString) {
+        const pathArray = [];
+        let state = 'empty';
+        let quote = 0;
+        let value = '';
+        let escaped = false;
+        for (const c of pathString) {
+            const v = c.codePointAt(0);
+            switch (state) {
+                case 'empty': // Empty
+                case 'id-start': // Expecting identifier start
+                    if (v === 0x5b) { // '['
+                        if (state === 'id-start') {
+                            throw new Error(`Unexpected character: ${c}`);
+                        }
+                        state = 'open-bracket';
+                    } else if (
+                        (v >= 0x41 && v <= 0x5a) || // ['A', 'Z']
+                        (v >= 0x61 && v <= 0x7a) || // ['a', 'z']
+                        v === 0x5f // '_'
+                    ) {
+                        state = 'id';
+                        value += c;
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'id': // Identifier
+                    if (
+                        (v >= 0x41 && v <= 0x5a) || // ['A', 'Z']
+                        (v >= 0x61 && v <= 0x7a) || // ['a', 'z']
+                        (v >= 0x30 && v <= 0x39) || // ['0', '9']
+                        v === 0x5f // '_'
+                    ) {
+                        value += c;
+                    } else if (v === 0x5b) { // '['
+                        pathArray.push(value);
+                        value = '';
+                        state = 'open-bracket';
+                    } else if (v === 0x2e) { // '.'
+                        pathArray.push(value);
+                        value = '';
+                        state = 'id-start';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'open-bracket': // Open bracket
+                    if (v === 0x22 || v === 0x27) { // '"' or '\''
+                        quote = v;
+                        state = 'string';
+                    } else if (v >= 0x30 && v <= 0x39) { // ['0', '9']
+                        state = 'number';
+                        value += c;
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'string': // Quoted string
+                    if (escaped) {
+                        value += c;
+                        escaped = false;
+                    } else if (v === 0x5c) { // '\\'
+                        escaped = true;
+                    } else if (v !== quote) {
+                        value += c;
+                    } else {
+                        state = 'close-bracket';
+                    }
+                    break;
+                case 'number': // Number
+                    if (v >= 0x30 && v <= 0x39) { // ['0', '9']
+                        value += c;
+                    } else if (v === 0x5d) { // ']'
+                        pathArray.push(Number.parseInt(value, 10));
+                        value = '';
+                        state = 'next';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'close-bracket': // Expecting closing bracket after quoted string
+                    if (v === 0x5d) { // ']'
+                        pathArray.push(value);
+                        value = '';
+                        state = 'next';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'next': // Expecting . or [
+                    if (v === 0x5b) { // '['
+                        state = 'open-bracket';
+                    } else if (v === 0x2e) { // '.'
+                        state = 'id-start';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+            }
+        }
+        switch (state) {
+            case 'empty':
+            case 'next':
+                break;
+            case 'id':
+                pathArray.push(value);
+                value = '';
+                break;
+            default:
+                throw new Error('Path not terminated correctly');
+        }
+        return pathArray;
+    }
+
+    static hasProperty(object, property) {
+        switch (typeof property) {
+            case 'string':
+                return (
+                    typeof object === 'object' &&
+                    object !== null &&
+                    !Array.isArray(object) &&
+                    Object.prototype.hasOwnProperty.call(object, property)
+                );
+            case 'number':
+                return (
+                    Array.isArray(object) &&
+                    property >= 0 &&
+                    property < object.length &&
+                    property === Math.floor(property)
+                );
+            default:
+                return false;
+        }
+    }
+
+    static isValidPropertyType(object, property) {
+        switch (typeof property) {
+            case 'string':
+                return (
+                    typeof object === 'object' &&
+                    object !== null &&
+                    !Array.isArray(object)
+                );
+            case 'number':
+                return (
+                    Array.isArray(object) &&
+                    property >= 0 &&
+                    property === Math.floor(property)
+                );
+            default:
+                return false;
+        }
+    }
+}
diff --git a/ext/mixed/js/text-scanner.js b/ext/mixed/js/text-scanner.js
index a08e09fb..b8156c01 100644
--- a/ext/mixed/js/text-scanner.js
+++ b/ext/mixed/js/text-scanner.js
@@ -23,13 +23,15 @@
  */
 
 class TextScanner {
-    constructor(node, ignoreNodes, ignoreElements, ignorePoints) {
+    constructor(node, ignoreElements, ignorePoints) {
         this.node = node;
-        this.ignoreNodes = (Array.isArray(ignoreNodes) && ignoreNodes.length > 0 ? ignoreNodes.join(',') : null);
         this.ignoreElements = ignoreElements;
         this.ignorePoints = ignorePoints;
 
+        this.ignoreNodes = null;
+
         this.scanTimerPromise = null;
+        this.causeCurrent = null;
         this.textSourceCurrent = null;
         this.pendingLookup = false;
         this.options = null;
@@ -298,6 +300,7 @@ class TextScanner {
                 this.pendingLookup = true;
                 const result = await this.onSearchSource(textSource, cause);
                 if (result !== null) {
+                    this.causeCurrent = cause;
                     this.textSourceCurrent = textSource;
                     if (this.options.scanning.selectText) {
                         textSource.select();
diff --git a/package-lock.json b/package-lock.json
index 88ba43f6..920263d2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -31,27 +31,19 @@
             "dev": true
         },
         "acorn": {
-            "version": "7.1.0",
-            "resolved": "https://registry.npmjs.org/acorn/-/acorn-7.1.0.tgz",
-            "integrity": "sha512-kL5CuoXA/dgxlBbVrflsflzQ3PAas7RYZB52NOm/6839iVYJgKMJ3cQJD+t2i5+qFa8h3MDpEOJiS64E8JLnSQ==",
+            "version": "7.1.1",
+            "resolved": "https://registry.npmjs.org/acorn/-/acorn-7.1.1.tgz",
+            "integrity": "sha512-add7dgA5ppRPxCFJoAGfMDi7PIBXq1RtGo7BhbLaxwrXPOmw8gq48Y9ozT01hUKy9byMjlR20EJhu5zlkErEkg==",
             "dev": true
         },
         "acorn-globals": {
-            "version": "4.3.4",
-            "resolved": "https://registry.npmjs.org/acorn-globals/-/acorn-globals-4.3.4.tgz",
-            "integrity": "sha512-clfQEh21R+D0leSbUdWf3OcfqyaCSAQ8Ryq00bofSekfr9W8u1jyYZo6ir0xu9Gtcf7BjcHJpnbZH7JOCpP60A==",
+            "version": "6.0.0",
+            "resolved": "https://registry.npmjs.org/acorn-globals/-/acorn-globals-6.0.0.tgz",
+            "integrity": "sha512-ZQl7LOWaF5ePqqcX4hLuv/bLXYQNfNWw2c0/yX/TsPRKamzHcTGQnlCjHT3TsmkOUVEPS3crCxiPfdzE/Trlhg==",
             "dev": true,
             "requires": {
-                "acorn": "^6.0.1",
-                "acorn-walk": "^6.0.1"
-            },
-            "dependencies": {
-                "acorn": {
-                    "version": "6.4.0",
-                    "resolved": "https://registry.npmjs.org/acorn/-/acorn-6.4.0.tgz",
-                    "integrity": "sha512-gac8OEcQ2Li1dxIEWGZzsp2BitJxwkwcOm0zHAJLcPJaVvm58FRnk6RkuLRpU1EujipU2ZFODv2P9DLMfnV8mw==",
-                    "dev": true
-                }
+                "acorn": "^7.1.1",
+                "acorn-walk": "^7.1.1"
             }
         },
         "acorn-jsx": {
@@ -61,9 +53,9 @@
             "dev": true
         },
         "acorn-walk": {
-            "version": "6.2.0",
-            "resolved": "https://registry.npmjs.org/acorn-walk/-/acorn-walk-6.2.0.tgz",
-            "integrity": "sha512-7evsyfH1cLOCdAzZAd43Cic04yKydNx0cF+7tiA19p1XnLLPU4dpCQOqpjqwokFe//vS0QqfqqjCS2JkiIs0cA==",
+            "version": "7.1.1",
+            "resolved": "https://registry.npmjs.org/acorn-walk/-/acorn-walk-7.1.1.tgz",
+            "integrity": "sha512-wdlPY2tm/9XBr7QkKlq0WQVgiuGTX6YWPyRyBviSoScBuLfTVQhvwg6wJ369GJ/1nPfTLMfnrFIfjqVg6d+jQQ==",
             "dev": true
         },
         "ajv": {
@@ -182,9 +174,9 @@
             }
         },
         "browser-process-hrtime": {
-            "version": "0.1.3",
-            "resolved": "https://registry.npmjs.org/browser-process-hrtime/-/browser-process-hrtime-0.1.3.tgz",
-            "integrity": "sha512-bRFnI4NnjO6cnyLmOV/7PVoDEMJChlcfN0z4s1YMBY989/SvlfMI1lgCnkFUs53e9gQF+w7qu7XdllSTiSl8Aw==",
+            "version": "1.0.0",
+            "resolved": "https://registry.npmjs.org/browser-process-hrtime/-/browser-process-hrtime-1.0.0.tgz",
+            "integrity": "sha512-9o5UecI3GhkpM6DrXr69PblIuWxPKk9Y0jHBRhdocZ2y7YECBFCsHm79Pr3OyR2AvjhDkabFJaDJMYRazHgsow==",
             "dev": true
         },
         "callsites": {
@@ -747,9 +739,9 @@
             "dev": true
         },
         "html-encoding-sniffer": {
-            "version": "2.0.0",
-            "resolved": "https://registry.npmjs.org/html-encoding-sniffer/-/html-encoding-sniffer-2.0.0.tgz",
-            "integrity": "sha512-Y9prnPKkM7FXxQevZ5UH8Z6aVTY0ede1tHquck5UxGmKWDshxXh95gSa2xXYjS8AsGO5iOvrCI5+GttRKnLdNA==",
+            "version": "2.0.1",
+            "resolved": "https://registry.npmjs.org/html-encoding-sniffer/-/html-encoding-sniffer-2.0.1.tgz",
+            "integrity": "sha512-D5JbOMBIR/TVZkubHT+OyT2705QvogUW4IBn6nHd756OwieSF9aDYFj4dv6HHEVGYbHaLETa3WggZYWWMyy3ZQ==",
             "dev": true,
             "requires": {
                 "whatwg-encoding": "^1.0.5"
@@ -914,30 +906,30 @@
             "dev": true
         },
         "jsdom": {
-            "version": "16.2.0",
-            "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-16.2.0.tgz",
-            "integrity": "sha512-6VaW3UWyKbm9DFVIAgTfhuwnvqiqlRYNg5Rk6dINTVoZT0eKz+N86vQZr+nqt1ny1lSB1TWZJWSEWQAfu8oTpA==",
+            "version": "16.2.1",
+            "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-16.2.1.tgz",
+            "integrity": "sha512-3p0gHs5EfT7PxW9v8Phz3mrq//4Dy8MQenU/PoKxhdT+c45S7NjIjKbGT3Ph0nkICweE1r36+yaknXA5WfVNAg==",
             "dev": true,
             "requires": {
                 "abab": "^2.0.3",
-                "acorn": "^7.1.0",
-                "acorn-globals": "^4.3.4",
+                "acorn": "^7.1.1",
+                "acorn-globals": "^6.0.0",
                 "cssom": "^0.4.4",
                 "cssstyle": "^2.2.0",
                 "data-urls": "^2.0.0",
                 "decimal.js": "^10.2.0",
                 "domexception": "^2.0.1",
-                "escodegen": "^1.13.0",
-                "html-encoding-sniffer": "^2.0.0",
+                "escodegen": "^1.14.1",
+                "html-encoding-sniffer": "^2.0.1",
                 "is-potential-custom-element-name": "^1.0.0",
                 "nwsapi": "^2.2.0",
                 "parse5": "5.1.1",
-                "request": "^2.88.0",
+                "request": "^2.88.2",
                 "request-promise-native": "^1.0.8",
-                "saxes": "^4.0.2",
+                "saxes": "^5.0.0",
                 "symbol-tree": "^3.2.4",
                 "tough-cookie": "^3.0.1",
-                "w3c-hr-time": "^1.0.1",
+                "w3c-hr-time": "^1.0.2",
                 "w3c-xmlserializer": "^2.0.0",
                 "webidl-conversions": "^5.0.0",
                 "whatwg-encoding": "^1.0.5",
@@ -1370,9 +1362,9 @@
             "dev": true
         },
         "saxes": {
-            "version": "4.0.2",
-            "resolved": "https://registry.npmjs.org/saxes/-/saxes-4.0.2.tgz",
-            "integrity": "sha512-EZOTeQ4bgkOaGCDaTKux+LaRNcLNbdbvMH7R3/yjEEULPEmqvkFbFub6DJhJTub2iGMT93CfpZ5LTdKZmAbVeQ==",
+            "version": "5.0.0",
+            "resolved": "https://registry.npmjs.org/saxes/-/saxes-5.0.0.tgz",
+            "integrity": "sha512-LXTZygxhf8lfwKaTP/8N9CsVdjTlea3teze4lL6u37ivbgGbV0GGMuNtS/I9rnD/HC2/txUM7Df4S2LVl1qhiA==",
             "dev": true,
             "requires": {
                 "xmlchars": "^2.2.0"
@@ -1690,12 +1682,12 @@
             }
         },
         "w3c-hr-time": {
-            "version": "1.0.1",
-            "resolved": "https://registry.npmjs.org/w3c-hr-time/-/w3c-hr-time-1.0.1.tgz",
-            "integrity": "sha1-gqwr/2PZUOqeMYmlimViX+3xkEU=",
+            "version": "1.0.2",
+            "resolved": "https://registry.npmjs.org/w3c-hr-time/-/w3c-hr-time-1.0.2.tgz",
+            "integrity": "sha512-z8P5DvDNjKDoFIHK7q8r8lackT6l+jo/Ye3HOle7l9nICP9lf1Ci25fy9vHd0JOWewkIFzXIEig3TdKT7JQ5fQ==",
             "dev": true,
             "requires": {
-                "browser-process-hrtime": "^0.1.2"
+                "browser-process-hrtime": "^1.0.0"
             }
         },
         "w3c-xmlserializer": {
@@ -1770,9 +1762,9 @@
             }
         },
         "ws": {
-            "version": "7.2.1",
-            "resolved": "https://registry.npmjs.org/ws/-/ws-7.2.1.tgz",
-            "integrity": "sha512-sucePNSafamSKoOqoNfBd8V0StlkzJKL2ZAhGQinCfNQ+oacw+Pk7lcdAElecBF2VkLNZRiIb5Oi1Q5lVUVt2A==",
+            "version": "7.2.3",
+            "resolved": "https://registry.npmjs.org/ws/-/ws-7.2.3.tgz",
+            "integrity": "sha512-HTDl9G9hbkNDk98naoR/cHDws7+EyYMOdL1BmjsZXRUjf7d+MficC4B7HLUPlSiho0vg+CWKrGIt/VJBd1xunQ==",
             "dev": true
         },
         "xml-name-validator": {
diff --git a/package.json b/package.json
index eb449ea9..b02ec179 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
     "scripts": {
         "test": "npm run test-lint && npm run test-code",
         "test-lint": "eslint . && node ./test/lint/global-declarations.js",
-        "test-code": "node ./test/test-schema.js && node ./test/test-dictionary.js && node ./test/test-database.js && node ./test/test-document.js"
+        "test-code": "node ./test/test-schema.js && node ./test/test-dictionary.js && node ./test/test-database.js && node ./test/test-document.js && node ./test/test-object-property-accessor.js && node ./test/test-japanese.js && node ./test/test-text-source-map.js"
     },
     "repository": {
         "type": "git",
@@ -30,6 +30,6 @@
         "eslint": "^6.8.0",
         "eslint-plugin-no-unsanitized": "^3.0.2",
         "fake-indexeddb": "^3.0.0",
-        "jsdom": "^16.2.0"
+        "jsdom": "^16.2.1"
     }
 }
diff --git a/test/data/dictionaries/valid-dictionary1/tag_bank_3.json b/test/data/dictionaries/valid-dictionary1/tag_bank_3.json
new file mode 100644
index 00000000..572221fe
--- /dev/null
+++ b/test/data/dictionaries/valid-dictionary1/tag_bank_3.json
@@ -0,0 +1,4 @@
+[
+    ["ptag1", "pcategory1", 0, "ptag1 notes", 0],
+    ["ptag2", "pcategory2", 0, "ptag2 notes", 0]
+]
\ No newline at end of file
diff --git a/test/data/dictionaries/valid-dictionary1/term_meta_bank_1.json b/test/data/dictionaries/valid-dictionary1/term_meta_bank_1.json
index 78096502..26922394 100644
--- a/test/data/dictionaries/valid-dictionary1/term_meta_bank_1.json
+++ b/test/data/dictionaries/valid-dictionary1/term_meta_bank_1.json
@@ -1,5 +1,39 @@
 [
     ["打", "freq", 1],
     ["打つ", "freq", 2],
-    ["打ち込む", "freq", 3]
+    ["打ち込む", "freq", 3],
+    [
+        "打ち込む",
+        "pitch",
+        {
+            "reading": "うちこむ",
+            "pitches": [
+                {"position": 0},
+                {"position": 3}
+            ]
+        }
+    ],
+    [
+        "打ち込む",
+        "pitch",
+        {
+            "reading": "ぶちこむ",
+            "pitches": [
+                {"position": 0},
+                {"position": 3}
+            ]
+        }
+    ],
+    [
+        "お手前",
+        "pitch",
+        {
+            "reading": "おてまえ",
+            "pitches": [
+                {"position": 2, "tags": ["ptag1"]},
+                {"position": 2, "tags": ["ptag2"]},
+                {"position": 0, "tags": ["ptag2"]}
+            ]
+        }
+    ]
 ]
\ No newline at end of file
diff --git a/test/data/html/test-document2-frame1.html b/test/data/html/test-document2-frame1.html
new file mode 100644
index 00000000..3b85cdc5
--- /dev/null
+++ b/test/data/html/test-document2-frame1.html
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width,initial-scale=1" />
+        <title>Yomichan Tests</title>
+        <script src="test-document2-script.js"></script>
+        <style>
+body {
+    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
+    font-size: 14px;
+    padding: 0;
+    margin: 0;
+    background-color: #f8f8f8;
+}
+a, a:visited {
+    color: #1080c0;
+    text-decoration: underline;
+}
+.content {
+    position: absolute;
+    left: 0;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    padding: 0.5em;
+    background-color: #f8f8f8;
+}
+        </style>
+    </head>
+<body><div class="content">
+<div>
+    ありがとう
+</div>
+<div>
+    <a href="#" id="fullscreen-link">Toggle fullscreen</a>
+    <script>
+document.querySelector('#fullscreen-link').addEventListener('click', () => toggleFullscreen(document.body), false);
+    </script>
+</div>
+</div></body>
+</html>
\ No newline at end of file
diff --git a/test/data/html/test-document2-script.js b/test/data/html/test-document2-script.js
new file mode 100644
index 00000000..bd5a570d
--- /dev/null
+++ b/test/data/html/test-document2-script.js
@@ -0,0 +1,41 @@
+function requestFullscreen(element) {
+    if (element.requestFullscreen) {
+        element.requestFullscreen();
+    } else if (element.mozRequestFullScreen) {
+        element.mozRequestFullScreen();
+    } else if (element.webkitRequestFullscreen) {
+        element.webkitRequestFullscreen();
+    } else if (element.msRequestFullscreen) {
+        element.msRequestFullscreen();
+    }
+}
+
+function exitFullscreen() {
+    if (document.exitFullscreen) {
+        document.exitFullscreen();
+    } else if (document.mozCancelFullScreen) {
+        document.mozCancelFullScreen();
+    } else if (document.webkitExitFullscreen) {
+        document.webkitExitFullscreen();
+    } else if (document.msExitFullscreen) {
+        document.msExitFullscreen();
+    }
+}
+
+function getFullscreenElement() {
+    return (
+        document.fullscreenElement ||
+        document.msFullscreenElement ||
+        document.mozFullScreenElement ||
+        document.webkitFullscreenElement ||
+        null
+    );
+}
+
+function toggleFullscreen(element) {
+    if (getFullscreenElement()) {
+        exitFullscreen();
+    } else {
+        requestFullscreen(element);
+    }
+}
diff --git a/test/data/html/test-document2.html b/test/data/html/test-document2.html
new file mode 100644
index 00000000..3a22a5bf
--- /dev/null
+++ b/test/data/html/test-document2.html
@@ -0,0 +1,81 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width,initial-scale=1" />
+        <title>Yomichan Manual Tests</title>
+        <link rel="icon" type="image/gif" href="data:image/gif;base64,R0lGODlhEAAQAKEBAAAAAP///////////yH5BAEKAAIALAAAAAAQABAAAAImFI6Zpt0B4YkS0TCpq07xbmEgcGVRUpLaI46ZG7ppalY0jDCwUAAAOw==" />
+        <link rel="stylesheet" href="test-stylesheet.css" />
+        <script src="test-document2-script.js"></script>
+    </head>
+<body>
+
+    <h1>Yomichan Manual Tests</h1>
+    <p class="description">Manual tests involving fullscreen elements, &lt;iframe&gt;s, and shadow DOMs.</p>
+
+    <div class="test">
+        <div class="description">Standard content.</div>
+        <div id="fullscreen-element1" style="width: 100%; height: 200px; border: 1px solid #d8d8d8; position: relative;"><div style="background-color: #f8f8f8; padding: 0.5em; position: absolute; left: 0; top: 0; bottom: 0; right: 0;">
+            <div>
+                ありがとう
+            </div>
+            <div>
+                <a href="#" id="fullscreen-link1">Toggle fullscreen</a>
+            </div>
+        </div></div>
+        <script>
+document.querySelector('#fullscreen-link1').addEventListener('click', () => toggleFullscreen(document.querySelector('#fullscreen-element1')), false);
+        </script>
+    </div>
+
+    <div class="test">
+        <div class="description">Content inside of a shadow DOM.</div>
+        <div id="shadow-content-container"></div>
+        <template id="shadow-content-container-content-template">
+            <link rel="stylesheet" href="test-stylesheet.css" />
+            <div id="fullscreen-element2" style="width: 100%; height: 200px; border: 1px solid #d8d8d8; position: relative;"><div style="background-color: #f8f8f8; padding: 0.5em; position: absolute; left: 0; top: 0; bottom: 0; right: 0;">
+                <div>
+                    ありがとう
+                </div>
+                <div>
+                    <a href="#" id="fullscreen-link2">Toggle fullscreen</a>
+                </div>
+            </div></div>
+        </template>
+        <script>
+(() => {
+    const shadowIframeContainer = document.querySelector('#shadow-content-container');
+    const shadow = shadowIframeContainer.attachShadow({mode: 'closed'});
+    const template = document.querySelector('#shadow-content-container-content-template').content;
+    const content = document.importNode(template, true);
+    const fullscreenElement = content.querySelector('#fullscreen-element2');
+    content.querySelector('#fullscreen-link2').addEventListener('click', () => toggleFullscreen(fullscreenElement), false);
+    shadow.appendChild(content);
+})();
+        </script>
+    </div>
+
+    <div class="test">
+        <div class="description">&lt;iframe&gt; element.</div>
+        <iframe src="test-document2-frame1.html" allowfullscreen="true" style="width: 100%; height: 200px; border: 1px solid #d8d8d8;"></iframe>
+    </div>
+
+    <div class="test">
+        <div class="description">&lt;iframe&gt; element inside of a shadow DOM.</div>
+        <div id="shadow-iframe-container"></div>
+        <template id="shadow-iframe-container-content-template">
+            <iframe src="test-document2-frame1.html" allowfullscreen="true" style="width: 100%; height: 200px; border: 1px solid #d8d8d8;"></iframe>
+        </template>
+        <script>
+(() => {
+    const shadowIframeContainer = document.querySelector('#shadow-iframe-container');
+    const shadow = shadowIframeContainer.attachShadow({mode: 'closed'});
+    const template = document.querySelector('#shadow-iframe-container-content-template').content;
+    const content = document.importNode(template, true);
+    shadow.appendChild(content);
+})();
+        </script>
+    </div>
+
+</body>
+</html>
\ No newline at end of file
diff --git a/test/data/html/test-stylesheet.css b/test/data/html/test-stylesheet.css
index ab25732e..f63d2481 100644
--- a/test/data/html/test-stylesheet.css
+++ b/test/data/html/test-stylesheet.css
@@ -7,6 +7,7 @@ body {
     margin: 0 auto;
     background-color: #f8f8f8;
     counter-reset: test-id;
+    overflow-y: scroll;
 }
 
 h1 {
@@ -14,6 +15,19 @@ h1 {
     margin: 0.67em 0;
 }
 
+p {
+    margin: 0.33em 0;
+}
+
+h1+p {
+    margin-top: -0.67em;
+}
+
+a, a:visited {
+    color: #1080c0;
+    text-decoration: underline;
+}
+
 .test {
     background-color: #ffffff;
     margin: 1em 0;
@@ -30,3 +44,8 @@ h1 {
     border-bottom: 1px solid #d8d8d8;
     font-weight: bold;
 }
+
+.description {
+    color: #444444;
+    font-style: italic;
+}
diff --git a/test/test-database.js b/test/test-database.js
index 833aa75d..bab15aa4 100644
--- a/test/test-database.js
+++ b/test/test-database.js
@@ -27,7 +27,8 @@ require('fake-indexeddb/auto');
 const chrome = {
     runtime: {
         onMessage: {
-            addListener() { /* NOP */ }
+            addListener() { /* NOP */ },
+            removeListener() { /* NOP */ }
         },
         getURL(path2) {
             return url.pathToFileURL(path.join(__dirname, '..', 'ext', path2.replace(/^\//, '')));
@@ -107,8 +108,10 @@ vm.execute([
     'bg/js/dictionary.js',
     'mixed/js/core.js',
     'bg/js/request.js',
+    'bg/js/dictionary-importer.js',
     'bg/js/database.js'
 ]);
+const DictionaryImporter = vm.get('DictionaryImporter');
 const Database = vm.get('Database');
 
 
@@ -196,6 +199,7 @@ async function testDatabase1() {
     ];
 
     // Setup database
+    const dictionaryImporter = new DictionaryImporter();
     const database = new Database();
     await database.prepare();
 
@@ -210,7 +214,8 @@ async function testDatabase1() {
 
         // Import data
         let progressEvent = false;
-        const {result, errors} = await database.importDictionary(
+        const {result, errors} = await dictionaryImporter.import(
+            database,
             testDictionarySource,
             () => {
                 progressEvent = true;
@@ -231,8 +236,8 @@ async function testDatabase1() {
             true
         );
         vm.assert.deepStrictEqual(counts, {
-            counts: [{kanji: 2, kanjiMeta: 2, terms: 32, termMeta: 3, tagMeta: 12}],
-            total: {kanji: 2, kanjiMeta: 2, terms: 32, termMeta: 3, tagMeta: 12}
+            counts: [{kanji: 2, kanjiMeta: 2, terms: 32, termMeta: 6, tagMeta: 14}],
+            total: {kanji: 2, kanjiMeta: 2, terms: 32, termMeta: 6, tagMeta: 14}
         });
 
         // Test find* functions
@@ -648,9 +653,10 @@ async function testFindTermMetaBulk1(database, titles) {
                 }
             ],
             expectedResults: {
-                total: 1,
+                total: 3,
                 modes: [
-                    ['freq', 1]
+                    ['freq', 1],
+                    ['pitch', 2]
                 ]
             }
         },
@@ -847,6 +853,7 @@ async function testDatabase2() {
     ]);
 
     // Setup database
+    const dictionaryImporter = new DictionaryImporter();
     const database = new Database();
 
     // Error: not prepared
@@ -862,17 +869,17 @@ async function testDatabase2() {
     await assert.rejects(async () => await database.findTagForTitle('tag', title));
     await assert.rejects(async () => await database.getDictionaryInfo());
     await assert.rejects(async () => await database.getDictionaryCounts(titles, true));
-    await assert.rejects(async () => await database.importDictionary(testDictionarySource, () => {}, {}));
+    await assert.rejects(async () => await dictionaryImporter.import(database, testDictionarySource, () => {}, {}));
 
     await database.prepare();
 
     // Error: already prepared
     await assert.rejects(async () => await database.prepare());
 
-    await database.importDictionary(testDictionarySource, () => {}, {});
+    await dictionaryImporter.import(database, testDictionarySource, () => {}, {});
 
     // Error: dictionary already imported
-    await assert.rejects(async () => await database.importDictionary(testDictionarySource, () => {}, {}));
+    await assert.rejects(async () => await dictionaryImporter.import(database, testDictionarySource, () => {}, {}));
 
     await database.close();
 }
@@ -889,6 +896,7 @@ async function testDatabase3() {
     ];
 
     // Setup database
+    const dictionaryImporter = new DictionaryImporter();
     const database = new Database();
     await database.prepare();
 
@@ -898,7 +906,7 @@ async function testDatabase3() {
 
         let error = null;
         try {
-            await database.importDictionary(testDictionarySource, () => {}, {});
+            await dictionaryImporter.import(database, testDictionarySource, () => {}, {});
         } catch (e) {
             error = e;
         }
diff --git a/test/test-japanese.js b/test/test-japanese.js
new file mode 100644
index 00000000..ca65dde2
--- /dev/null
+++ b/test/test-japanese.js
@@ -0,0 +1,471 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const assert = require('assert');
+const {VM} = require('./yomichan-vm');
+
+const vm = new VM();
+vm.execute([
+    'mixed/lib/wanakana.min.js',
+    'mixed/js/japanese.js',
+    'bg/js/text-source-map.js',
+    'bg/js/japanese.js'
+]);
+const jp = vm.get('jp');
+const TextSourceMap = vm.get('TextSourceMap');
+
+
+function testIsCodePointKanji() {
+    const data = [
+        ['力方', true],
+        ['\u53f1\u{20b9f}', true],
+        ['かたカタ々kata、。？,.?', false]
+    ];
+
+    for (const [characters, expected] of data) {
+        for (const character of characters) {
+            const codePoint = character.codePointAt(0);
+            const actual = jp.isCodePointKanji(codePoint);
+            assert.strictEqual(actual, expected, `isCodePointKanji failed for ${character} (\\u{${codePoint.toString(16)}})`);
+        }
+    }
+}
+
+function testIsCodePointKana() {
+    const data = [
+        ['かたカタ', true],
+        ['力方々kata、。？,.?', false],
+        ['\u53f1\u{20b9f}', false]
+    ];
+
+    for (const [characters, expected] of data) {
+        for (const character of characters) {
+            const codePoint = character.codePointAt(0);
+            const actual = jp.isCodePointKana(codePoint);
+            assert.strictEqual(actual, expected, `isCodePointKana failed for ${character} (\\u{${codePoint.toString(16)}})`);
+        }
+    }
+}
+
+function testIsCodePointJapanese() {
+    const data = [
+        ['かたカタ力方々、。？', true],
+        ['\u53f1\u{20b9f}', true],
+        ['kata,.?', false]
+    ];
+
+    for (const [characters, expected] of data) {
+        for (const character of characters) {
+            const codePoint = character.codePointAt(0);
+            const actual = jp.isCodePointJapanese(codePoint);
+            assert.strictEqual(actual, expected, `isCodePointJapanese failed for ${character} (\\u{${codePoint.toString(16)}})`);
+        }
+    }
+}
+
+function testIsStringEntirelyKana() {
+    const data = [
+        ['かたかな', true],
+        ['カタカナ', true],
+        ['ひらがな', true],
+        ['ヒラガナ', true],
+        ['カタカナひらがな', true],
+        ['かたカタ力方々、。？', false],
+        ['\u53f1\u{20b9f}', false],
+        ['kata,.?', false],
+        ['かたカタ力方々、。？invalid', false],
+        ['\u53f1\u{20b9f}invalid', false],
+        ['kata,.?かた', false]
+    ];
+
+    for (const [string, expected] of data) {
+        assert.strictEqual(jp.isStringEntirelyKana(string), expected);
+    }
+}
+
+function testIsStringPartiallyJapanese() {
+    const data = [
+        ['かたかな', true],
+        ['カタカナ', true],
+        ['ひらがな', true],
+        ['ヒラガナ', true],
+        ['カタカナひらがな', true],
+        ['かたカタ力方々、。？', true],
+        ['\u53f1\u{20b9f}', true],
+        ['kata,.?', false],
+        ['かたカタ力方々、。？invalid', true],
+        ['\u53f1\u{20b9f}invalid', true],
+        ['kata,.?かた', true]
+    ];
+
+    for (const [string, expected] of data) {
+        assert.strictEqual(jp.isStringPartiallyJapanese(string), expected);
+    }
+}
+
+function testConvertKatakanaToHiragana() {
+    const data = [
+        ['かたかな', 'かたかな'],
+        ['ひらがな', 'ひらがな'],
+        ['カタカナ', 'かたかな'],
+        ['ヒラガナ', 'ひらがな'],
+        ['カタカナかたかな', 'かたかなかたかな'],
+        ['ヒラガナひらがな', 'ひらがなひらがな'],
+        ['chikaraちからチカラ力', 'chikaraちからちから力'],
+        ['katakana', 'katakana'],
+        ['hiragana', 'hiragana']
+    ];
+
+    for (const [string, expected] of data) {
+        assert.strictEqual(jp.convertKatakanaToHiragana(string), expected);
+    }
+}
+
+function testConvertHiraganaToKatakana() {
+    const data = [
+        ['かたかな', 'カタカナ'],
+        ['ひらがな', 'ヒラガナ'],
+        ['カタカナ', 'カタカナ'],
+        ['ヒラガナ', 'ヒラガナ'],
+        ['カタカナかたかな', 'カタカナカタカナ'],
+        ['ヒラガナひらがな', 'ヒラガナヒラガナ'],
+        ['chikaraちからチカラ力', 'chikaraチカラチカラ力'],
+        ['katakana', 'katakana'],
+        ['hiragana', 'hiragana']
+    ];
+
+    for (const [string, expected] of data) {
+        assert.strictEqual(jp.convertHiraganaToKatakana(string), expected);
+    }
+}
+
+function testConvertToRomaji() {
+    const data = [
+        ['かたかな', 'katakana'],
+        ['ひらがな', 'hiragana'],
+        ['カタカナ', 'katakana'],
+        ['ヒラガナ', 'hiragana'],
+        ['カタカナかたかな', 'katakanakatakana'],
+        ['ヒラガナひらがな', 'hiraganahiragana'],
+        ['chikaraちからチカラ力', 'chikarachikarachikara力'],
+        ['katakana', 'katakana'],
+        ['hiragana', 'hiragana']
+    ];
+
+    for (const [string, expected] of data) {
+        assert.strictEqual(jp.convertToRomaji(string), expected);
+    }
+}
+
+function testConvertReading() {
+    const data = [
+        [['アリガトウ', 'アリガトウ', 'hiragana'], 'ありがとう'],
+        [['アリガトウ', 'アリガトウ', 'katakana'], 'アリガトウ'],
+        [['アリガトウ', 'アリガトウ', 'romaji'], 'arigatou'],
+        [['アリガトウ', 'アリガトウ', 'none'], null],
+        [['アリガトウ', 'アリガトウ', 'default'], 'アリガトウ'],
+
+        [['ありがとう', 'ありがとう', 'hiragana'], 'ありがとう'],
+        [['ありがとう', 'ありがとう', 'katakana'], 'アリガトウ'],
+        [['ありがとう', 'ありがとう', 'romaji'], 'arigatou'],
+        [['ありがとう', 'ありがとう', 'none'], null],
+        [['ありがとう', 'ありがとう', 'default'], 'ありがとう'],
+
+        [['有り難う', 'ありがとう', 'hiragana'], 'ありがとう'],
+        [['有り難う', 'ありがとう', 'katakana'], 'アリガトウ'],
+        [['有り難う', 'ありがとう', 'romaji'], 'arigatou'],
+        [['有り難う', 'ありがとう', 'none'], null],
+        [['有り難う', 'ありがとう', 'default'], 'ありがとう'],
+
+        // Cases with falsy readings
+
+        [['ありがとう', '', 'hiragana'], ''],
+        [['ありがとう', '', 'katakana'], ''],
+        [['ありがとう', '', 'romaji'], 'arigatou'],
+        [['ありがとう', '', 'none'], null],
+        [['ありがとう', '', 'default'], ''],
+
+        [['ありがとう', null, 'hiragana'], ''],
+        [['ありがとう', null, 'katakana'], ''],
+        [['ありがとう', null, 'romaji'], 'arigatou'],
+        [['ありがとう', null, 'none'], null],
+        [['ありがとう', null, 'default'], null],
+
+        [['ありがとう', void 0, 'hiragana'], ''],
+        [['ありがとう', void 0, 'katakana'], ''],
+        [['ありがとう', void 0, 'romaji'], 'arigatou'],
+        [['ありがとう', void 0, 'none'], null],
+        [['ありがとう', void 0, 'default'], void 0],
+
+        // Cases with falsy readings and kanji expressions
+
+        [['有り難う', '', 'hiragana'], ''],
+        [['有り難う', '', 'katakana'], ''],
+        [['有り難う', '', 'romaji'], ''],
+        [['有り難う', '', 'none'], null],
+        [['有り難う', '', 'default'], ''],
+
+        [['有り難う', null, 'hiragana'], ''],
+        [['有り難う', null, 'katakana'], ''],
+        [['有り難う', null, 'romaji'], null],
+        [['有り難う', null, 'none'], null],
+        [['有り難う', null, 'default'], null],
+
+        [['有り難う', void 0, 'hiragana'], ''],
+        [['有り難う', void 0, 'katakana'], ''],
+        [['有り難う', void 0, 'romaji'], void 0],
+        [['有り難う', void 0, 'none'], null],
+        [['有り難う', void 0, 'default'], void 0]
+    ];
+
+    for (const [[expressionFragment, readingFragment, readingMode], expected] of data) {
+        assert.strictEqual(jp.convertReading(expressionFragment, readingFragment, readingMode), expected);
+    }
+}
+
+function testConvertNumericToFullWidth() {
+    const data = [
+        ['0123456789', '０１２３４５６７８９'],
+        ['abcdefghij', 'abcdefghij'],
+        ['カタカナ', 'カタカナ'],
+        ['ひらがな', 'ひらがな']
+    ];
+
+    for (const [string, expected] of data) {
+        assert.strictEqual(jp.convertNumericToFullWidth(string), expected);
+    }
+}
+
+function testConvertHalfWidthKanaToFullWidth() {
+    const data = [
+        ['0123456789', '0123456789'],
+        ['abcdefghij', 'abcdefghij'],
+        ['カタカナ', 'カタカナ'],
+        ['ひらがな', 'ひらがな'],
+        ['ｶｷ', 'カキ', [1, 1]],
+        ['ｶﾞｷ', 'ガキ', [2, 1]],
+        ['ﾆﾎﾝ', 'ニホン', [1, 1, 1]],
+        ['ﾆｯﾎﾟﾝ', 'ニッポン', [1, 1, 2, 1]]
+    ];
+
+    for (const [string, expected, expectedSourceMapping] of data) {
+        const sourceMap = new TextSourceMap(string);
+        const actual1 = jp.convertHalfWidthKanaToFullWidth(string, null);
+        const actual2 = jp.convertHalfWidthKanaToFullWidth(string, sourceMap);
+        assert.strictEqual(actual1, expected);
+        assert.strictEqual(actual2, expected);
+        if (typeof expectedSourceMapping !== 'undefined') {
+            assert.ok(sourceMap.equals(new TextSourceMap(string, expectedSourceMapping)));
+        }
+    }
+}
+
+function testConvertAlphabeticToKana() {
+    const data = [
+        ['0123456789', '0123456789'],
+        ['abcdefghij', 'あbcでfgひj', [1, 1, 1, 2, 1, 1, 2, 1]],
+        ['ABCDEFGHIJ', 'あbcでfgひj', [1, 1, 1, 2, 1, 1, 2, 1]], // wanakana.toHiragana converts text to lower case
+        ['カタカナ', 'カタカナ'],
+        ['ひらがな', 'ひらがな'],
+        ['chikara', 'ちから', [3, 2, 2]],
+        ['CHIKARA', 'ちから', [3, 2, 2]]
+    ];
+
+    for (const [string, expected, expectedSourceMapping] of data) {
+        const sourceMap = new TextSourceMap(string);
+        const actual1 = jp.convertAlphabeticToKana(string, null);
+        const actual2 = jp.convertAlphabeticToKana(string, sourceMap);
+        assert.strictEqual(actual1, expected);
+        assert.strictEqual(actual2, expected);
+        if (typeof expectedSourceMapping !== 'undefined') {
+            assert.ok(sourceMap.equals(new TextSourceMap(string, expectedSourceMapping)));
+        }
+    }
+}
+
+function testDistributeFurigana() {
+    const data = [
+        [
+            ['有り難う', 'ありがとう'],
+            [
+                {text: '有', furigana: 'あ'},
+                {text: 'り'},
+                {text: '難', furigana: 'がと'},
+                {text: 'う'}
+            ]
+        ],
+        [
+            ['方々', 'かたがた'],
+            [
+                {text: '方々', furigana: 'かたがた'}
+            ]
+        ],
+        [
+            ['お祝い', 'おいわい'],
+            [
+                {text: 'お'},
+                {text: '祝', furigana: 'いわ'},
+                {text: 'い'}
+            ]
+        ],
+        [
+            ['美味しい', 'おいしい'],
+            [
+                {text: '美味', furigana: 'おい'},
+                {text: 'しい'}
+            ]
+        ],
+        [
+            ['食べ物', 'たべもの'],
+            [
+                {text: '食', furigana: 'た'},
+                {text: 'べ'},
+                {text: '物', furigana: 'もの'}
+            ]
+        ],
+        [
+            ['試し切り', 'ためしぎり'],
+            [
+                {text: '試', furigana: 'ため'},
+                {text: 'し'},
+                {text: '切', furigana: 'ぎ'},
+                {text: 'り'}
+            ]
+        ],
+        // Ambiguous
+        [
+            ['飼い犬', 'かいいぬ'],
+            [
+                {text: '飼い犬', furigana: 'かいいぬ'}
+            ]
+        ],
+        [
+            ['長い間', 'ながいあいだ'],
+            [
+                {text: '長い間', furigana: 'ながいあいだ'}
+            ]
+        ]
+    ];
+
+    for (const [[expression, reading], expected] of data) {
+        const actual = jp.distributeFurigana(expression, reading);
+        vm.assert.deepStrictEqual(actual, expected);
+    }
+}
+
+function testDistributeFuriganaInflected() {
+    const data = [
+        [
+            ['美味しい', 'おいしい', '美味しかた'],
+            [
+                {text: '美味', furigana: 'おい'},
+                {text: 'し'},
+                {text: 'かた'}
+            ]
+        ],
+        [
+            ['食べる', 'たべる', '食べた'],
+            [
+                {text: '食', furigana: 'た'},
+                {text: 'べ'},
+                {text: 'た'}
+            ]
+        ]
+    ];
+
+    for (const [[expression, reading, source], expected] of data) {
+        const actual = jp.distributeFuriganaInflected(expression, reading, source);
+        vm.assert.deepStrictEqual(actual, expected);
+    }
+}
+
+function testIsMoraPitchHigh() {
+    const data = [
+        [[0, 0], false],
+        [[1, 0], true],
+        [[2, 0], true],
+        [[3, 0], true],
+
+        [[0, 1], true],
+        [[1, 1], false],
+        [[2, 1], false],
+        [[3, 1], false],
+
+        [[0, 2], true],
+        [[1, 2], true],
+        [[2, 2], false],
+        [[3, 2], false],
+
+        [[0, 3], true],
+        [[1, 3], true],
+        [[2, 3], true],
+        [[3, 3], false],
+
+        [[0, 4], true],
+        [[1, 4], true],
+        [[2, 4], true],
+        [[3, 4], true]
+    ];
+
+    for (const [[moraIndex, pitchAccentPosition], expected] of data) {
+        const actual = jp.isMoraPitchHigh(moraIndex, pitchAccentPosition);
+        assert.strictEqual(actual, expected);
+    }
+}
+
+function testGetKanaMorae() {
+    const data = [
+        ['かこ', ['か', 'こ']],
+        ['かっこ', ['か', 'っ', 'こ']],
+        ['カコ', ['カ', 'コ']],
+        ['カッコ', ['カ', 'ッ', 'コ']],
+        ['コート', ['コ', 'ー', 'ト']],
+        ['ちゃんと', ['ちゃ', 'ん', 'と']],
+        ['とうきょう', ['と', 'う', 'きょ', 'う']],
+        ['ぎゅう', ['ぎゅ', 'う']],
+        ['ディスコ', ['ディ', 'ス', 'コ']]
+    ];
+
+    for (const [text, expected] of data) {
+        const actual = jp.getKanaMorae(text);
+        vm.assert.deepStrictEqual(actual, expected);
+    }
+}
+
+
+function main() {
+    testIsCodePointKanji();
+    testIsCodePointKana();
+    testIsCodePointJapanese();
+    testIsStringEntirelyKana();
+    testIsStringPartiallyJapanese();
+    testConvertKatakanaToHiragana();
+    testConvertHiraganaToKatakana();
+    testConvertToRomaji();
+    testConvertReading();
+    testConvertNumericToFullWidth();
+    testConvertHalfWidthKanaToFullWidth();
+    testConvertAlphabeticToKana();
+    testDistributeFurigana();
+    testDistributeFuriganaInflected();
+    testIsMoraPitchHigh();
+    testGetKanaMorae();
+}
+
+
+if (require.main === module) { main(); }
diff --git a/test/test-object-property-accessor.js b/test/test-object-property-accessor.js
new file mode 100644
index 00000000..47d2e451
--- /dev/null
+++ b/test/test-object-property-accessor.js
@@ -0,0 +1,289 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const assert = require('assert');
+const {VM} = require('./yomichan-vm');
+
+const vm = new VM({});
+vm.execute('mixed/js/object-property-accessor.js');
+const ObjectPropertyAccessor = vm.get('ObjectPropertyAccessor');
+
+
+function createTestObject() {
+    return {
+        0: null,
+        value1: {
+            value2: {},
+            value3: [],
+            value4: null
+        },
+        value5: [
+            {},
+            [],
+            null
+        ]
+    };
+}
+
+
+function testGetProperty1() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    const data = [
+        [[], object],
+        [['0'], object['0']],
+        [['value1'], object.value1],
+        [['value1', 'value2'], object.value1.value2],
+        [['value1', 'value3'], object.value1.value3],
+        [['value1', 'value4'], object.value1.value4],
+        [['value5'], object.value5],
+        [['value5', 0], object.value5[0]],
+        [['value5', 1], object.value5[1]],
+        [['value5', 2], object.value5[2]]
+    ];
+
+    for (const [pathArray, expected] of data) {
+        assert.strictEqual(accessor.getProperty(pathArray), expected);
+    }
+}
+
+function testGetProperty2() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    const data = [
+        [[0], 'Invalid path: [0]'],
+        [['0', 'invalid'], 'Invalid path: ["0"].invalid'],
+        [['invalid'], 'Invalid path: invalid'],
+        [['value1', 'invalid'], 'Invalid path: value1.invalid'],
+        [['value1', 'value2', 'invalid'], 'Invalid path: value1.value2.invalid'],
+        [['value1', 'value2', 0], 'Invalid path: value1.value2[0]'],
+        [['value1', 'value3', 'invalid'], 'Invalid path: value1.value3.invalid'],
+        [['value1', 'value3', 0], 'Invalid path: value1.value3[0]'],
+        [['value1', 'value4', 'invalid'], 'Invalid path: value1.value4.invalid'],
+        [['value1', 'value4', 0], 'Invalid path: value1.value4[0]'],
+        [['value5', 'length'], 'Invalid path: value5.length'],
+        [['value5', 0, 'invalid'], 'Invalid path: value5[0].invalid'],
+        [['value5', 0, 0], 'Invalid path: value5[0][0]'],
+        [['value5', 1, 'invalid'], 'Invalid path: value5[1].invalid'],
+        [['value5', 1, 0], 'Invalid path: value5[1][0]'],
+        [['value5', 2, 'invalid'], 'Invalid path: value5[2].invalid'],
+        [['value5', 2, 0], 'Invalid path: value5[2][0]'],
+        [['value5', 2, 0, 'invalid'], 'Invalid path: value5[2][0]'],
+        [['value5', 2.5], 'Invalid index']
+    ];
+
+    for (const [pathArray, message] of data) {
+        assert.throws(() => accessor.getProperty(pathArray), {message});
+    }
+}
+
+
+function testSetProperty1() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    const testValue = {};
+    const data = [
+        ['0'],
+        ['value1', 'value2'],
+        ['value1', 'value3'],
+        ['value1', 'value4'],
+        ['value1'],
+        ['value5', 0],
+        ['value5', 1],
+        ['value5', 2],
+        ['value5']
+    ];
+
+    for (const pathArray of data) {
+        accessor.setProperty(pathArray, testValue);
+        assert.strictEqual(accessor.getProperty(pathArray), testValue);
+    }
+}
+
+function testSetProperty2() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    const testValue = {};
+    const data = [
+        [[0], 'Invalid path: [0]'],
+        [['0', 'invalid'], 'Invalid path: ["0"].invalid'],
+        [['value1', 'value2', 0], 'Invalid path: value1.value2[0]'],
+        [['value1', 'value3', 'invalid'], 'Invalid path: value1.value3.invalid'],
+        [['value1', 'value4', 'invalid'], 'Invalid path: value1.value4.invalid'],
+        [['value1', 'value4', 0], 'Invalid path: value1.value4[0]'],
+        [['value5', 1, 'invalid'], 'Invalid path: value5[1].invalid'],
+        [['value5', 2, 'invalid'], 'Invalid path: value5[2].invalid'],
+        [['value5', 2, 0], 'Invalid path: value5[2][0]'],
+        [['value5', 2, 0, 'invalid'], 'Invalid path: value5[2][0]'],
+        [['value5', 2.5], 'Invalid index']
+    ];
+
+    for (const [pathArray, message] of data) {
+        assert.throws(() => accessor.setProperty(pathArray, testValue), {message});
+    }
+}
+
+
+function testGetPathString1() {
+    const data = [
+        [[], ''],
+        [[0], '[0]'],
+        [['escape\\'], '["escape\\\\"]'],
+        [['\'quote\''], '["\'quote\'"]'],
+        [['"quote"'], '["\\"quote\\""]'],
+        [['part1', 'part2'], 'part1.part2'],
+        [['part1', 'part2', 3], 'part1.part2[3]'],
+        [['part1', 'part2', '3'], 'part1.part2["3"]'],
+        [['part1', 'part2', '3part'], 'part1.part2["3part"]'],
+        [['part1', 'part2', '3part', 'part4'], 'part1.part2["3part"].part4'],
+        [['part1', 'part2', '3part', '4part'], 'part1.part2["3part"]["4part"]']
+    ];
+
+    for (const [pathArray, expected] of data) {
+        assert.strictEqual(ObjectPropertyAccessor.getPathString(pathArray), expected);
+    }
+}
+
+function testGetPathString2() {
+    const data = [
+        [[1.5], 'Invalid index'],
+        [[null], 'Invalid type: object']
+    ];
+
+    for (const [pathArray, message] of data) {
+        assert.throws(() => ObjectPropertyAccessor.getPathString(pathArray), {message});
+    }
+}
+
+
+function testGetPathArray1() {
+    const data = [
+        ['', []],
+        ['[0]', [0]],
+        ['["escape\\\\"]', ['escape\\']],
+        ['["\'quote\'"]', ['\'quote\'']],
+        ['["\\"quote\\""]', ['"quote"']],
+        ['part1.part2', ['part1', 'part2']],
+        ['part1.part2[3]', ['part1', 'part2', 3]],
+        ['part1.part2["3"]', ['part1', 'part2', '3']],
+        ['part1.part2[\'3\']', ['part1', 'part2', '3']],
+        ['part1.part2["3part"]', ['part1', 'part2', '3part']],
+        ['part1.part2[\'3part\']', ['part1', 'part2', '3part']],
+        ['part1.part2["3part"].part4', ['part1', 'part2', '3part', 'part4']],
+        ['part1.part2[\'3part\'].part4', ['part1', 'part2', '3part', 'part4']],
+        ['part1.part2["3part"]["4part"]', ['part1', 'part2', '3part', '4part']],
+        ['part1.part2[\'3part\'][\'4part\']', ['part1', 'part2', '3part', '4part']]
+    ];
+
+    for (const [pathString, expected] of data) {
+        vm.assert.deepStrictEqual(ObjectPropertyAccessor.getPathArray(pathString), expected);
+    }
+}
+
+function testGetPathArray2() {
+    const data = [
+        ['?', 'Unexpected character: ?'],
+        ['.', 'Unexpected character: .'],
+        ['0', 'Unexpected character: 0'],
+        ['part1.[0]', 'Unexpected character: ['],
+        ['part1?', 'Unexpected character: ?'],
+        ['[part1]', 'Unexpected character: p'],
+        ['[0a]', 'Unexpected character: a'],
+        ['["part1"x]', 'Unexpected character: x'],
+        ['[\'part1\'x]', 'Unexpected character: x'],
+        ['["part1"]x', 'Unexpected character: x'],
+        ['[\'part1\']x', 'Unexpected character: x'],
+        ['part1..part2', 'Unexpected character: .'],
+
+        ['[', 'Path not terminated correctly'],
+        ['part1.', 'Path not terminated correctly'],
+        ['part1[', 'Path not terminated correctly'],
+        ['part1["', 'Path not terminated correctly'],
+        ['part1[\'', 'Path not terminated correctly'],
+        ['part1[""', 'Path not terminated correctly'],
+        ['part1[\'\'', 'Path not terminated correctly'],
+        ['part1[0', 'Path not terminated correctly'],
+        ['part1[0].', 'Path not terminated correctly']
+    ];
+
+    for (const [pathString, message] of data) {
+        assert.throws(() => ObjectPropertyAccessor.getPathArray(pathString), {message});
+    }
+}
+
+
+function testHasProperty() {
+    const data = [
+        [{}, 'invalid', false],
+        [{}, 0, false],
+        [{valid: 0}, 'valid', true],
+        [{null: 0}, null, false],
+        [[], 'invalid', false],
+        [[], 0, false],
+        [[0], 0, true],
+        [[0], null, false],
+        ['string', 0, false],
+        ['string', 'length', false],
+        ['string', null, false]
+    ];
+
+    for (const [object, property, expected] of data) {
+        assert.strictEqual(ObjectPropertyAccessor.hasProperty(object, property), expected);
+    }
+}
+
+function testIsValidPropertyType() {
+    const data = [
+        [{}, 'invalid', true],
+        [{}, 0, false],
+        [{valid: 0}, 'valid', true],
+        [{null: 0}, null, false],
+        [[], 'invalid', false],
+        [[], 0, true],
+        [[0], 0, true],
+        [[0], null, false],
+        ['string', 0, false],
+        ['string', 'length', false],
+        ['string', null, false]
+    ];
+
+    for (const [object, property, expected] of data) {
+        assert.strictEqual(ObjectPropertyAccessor.isValidPropertyType(object, property), expected);
+    }
+}
+
+
+function main() {
+    testGetProperty1();
+    testGetProperty2();
+    testSetProperty1();
+    testSetProperty2();
+    testGetPathString1();
+    testGetPathString2();
+    testGetPathArray1();
+    testGetPathArray2();
+    testHasProperty();
+    testIsValidPropertyType();
+}
+
+
+if (require.main === module) { main(); }
diff --git a/test/test-text-source-map.js b/test/test-text-source-map.js
new file mode 100644
index 00000000..25bd8fc2
--- /dev/null
+++ b/test/test-text-source-map.js
@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const assert = require('assert');
+const {VM} = require('./yomichan-vm');
+
+const vm = new VM();
+vm.execute(['bg/js/text-source-map.js']);
+const TextSourceMap = vm.get('TextSourceMap');
+
+
+function testSource() {
+    const data = [
+        ['source1'],
+        ['source2'],
+        ['source3']
+    ];
+
+    for (const [source] of data) {
+        const sourceMap = new TextSourceMap(source);
+        assert.strictEqual(source, sourceMap.source);
+    }
+}
+
+function testEquals() {
+    const data = [
+        [['source1', null], ['source1', null], true],
+        [['source2', null], ['source2', null], true],
+        [['source3', null], ['source3', null], true],
+
+        [['source1', [1, 1, 1, 1, 1, 1, 1]], ['source1', null], true],
+        [['source2', [1, 1, 1, 1, 1, 1, 1]], ['source2', null], true],
+        [['source3', [1, 1, 1, 1, 1, 1, 1]], ['source3', null], true],
+
+        [['source1', null], ['source1', [1, 1, 1, 1, 1, 1, 1]], true],
+        [['source2', null], ['source2', [1, 1, 1, 1, 1, 1, 1]], true],
+        [['source3', null], ['source3', [1, 1, 1, 1, 1, 1, 1]], true],
+
+        [['source1', [1, 1, 1, 1, 1, 1, 1]], ['source1', [1, 1, 1, 1, 1, 1, 1]], true],
+        [['source2', [1, 1, 1, 1, 1, 1, 1]], ['source2', [1, 1, 1, 1, 1, 1, 1]], true],
+        [['source3', [1, 1, 1, 1, 1, 1, 1]], ['source3', [1, 1, 1, 1, 1, 1, 1]], true],
+
+        [['source1', [1, 2, 1, 3]], ['source1', [1, 2, 1, 3]], true],
+        [['source2', [1, 2, 1, 3]], ['source2', [1, 2, 1, 3]], true],
+        [['source3', [1, 2, 1, 3]], ['source3', [1, 2, 1, 3]], true],
+
+        [['source1', [1, 3, 1, 2]], ['source1', [1, 2, 1, 3]], false],
+        [['source2', [1, 3, 1, 2]], ['source2', [1, 2, 1, 3]], false],
+        [['source3', [1, 3, 1, 2]], ['source3', [1, 2, 1, 3]], false],
+
+        [['source1', [1, 1, 1, 1, 1, 1, 1]], ['source4', [1, 1, 1, 1, 1, 1, 1]], false],
+        [['source2', [1, 1, 1, 1, 1, 1, 1]], ['source5', [1, 1, 1, 1, 1, 1, 1]], false],
+        [['source3', [1, 1, 1, 1, 1, 1, 1]], ['source6', [1, 1, 1, 1, 1, 1, 1]], false]
+    ];
+
+    for (const [[source1, mapping1], [source2, mapping2], expectedEquals] of data) {
+        const sourceMap1 = new TextSourceMap(source1, mapping1);
+        const sourceMap2 = new TextSourceMap(source2, mapping2);
+        assert.ok(sourceMap1.equals(sourceMap1));
+        assert.ok(sourceMap2.equals(sourceMap2));
+        assert.strictEqual(sourceMap1.equals(sourceMap2), expectedEquals);
+    }
+}
+
+function testGetSourceLength() {
+    const data = [
+        [['source', [1, 1, 1, 1, 1, 1]], 1, 1],
+        [['source', [1, 1, 1, 1, 1, 1]], 2, 2],
+        [['source', [1, 1, 1, 1, 1, 1]], 3, 3],
+        [['source', [1, 1, 1, 1, 1, 1]], 4, 4],
+        [['source', [1, 1, 1, 1, 1, 1]], 5, 5],
+        [['source', [1, 1, 1, 1, 1, 1]], 6, 6],
+
+        [['source', [2, 2, 2]], 1, 2],
+        [['source', [2, 2, 2]], 2, 4],
+        [['source', [2, 2, 2]], 3, 6],
+
+        [['source', [3, 3]], 1, 3],
+        [['source', [3, 3]], 2, 6],
+
+        [['source', [6, 6]], 1, 6]
+    ];
+
+    for (const [[source, mapping], finalLength, expectedValue] of data) {
+        const sourceMap = new TextSourceMap(source, mapping);
+        assert.strictEqual(sourceMap.getSourceLength(finalLength), expectedValue);
+    }
+}
+
+function testCombineInsert() {
+    const data = [
+        // No operations
+        [
+            ['source', null],
+            ['source', [1, 1, 1, 1, 1, 1]],
+            []
+        ],
+
+        // Combine
+        [
+            ['source', null],
+            ['source', [3, 1, 1, 1]],
+            [
+                ['combine', 0, 2]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [1, 1, 1, 3]],
+            [
+                ['combine', 3, 2]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [3, 3]],
+            [
+                ['combine', 0, 2],
+                ['combine', 1, 2]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [3, 3]],
+            [
+                ['combine', 3, 2],
+                ['combine', 0, 2]
+            ]
+        ],
+
+        // Insert
+        [
+            ['source', null],
+            ['source', [0, 1, 1, 1, 1, 1, 1]],
+            [
+                ['insert', 0, 0]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [1, 1, 1, 1, 1, 1, 0]],
+            [
+                ['insert', 6, 0]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [0, 1, 1, 1, 1, 1, 1, 0]],
+            [
+                ['insert', 0, 0],
+                ['insert', 7, 0]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [0, 1, 1, 1, 1, 1, 1, 0]],
+            [
+                ['insert', 6, 0],
+                ['insert', 0, 0]
+            ]
+        ],
+
+        // Mixed
+        [
+            ['source', null],
+            ['source', [3, 0, 3]],
+            [
+                ['combine', 0, 2],
+                ['insert', 1, 0],
+                ['combine', 2, 2]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [3, 0, 3]],
+            [
+                ['combine', 0, 2],
+                ['combine', 1, 2],
+                ['insert', 1, 0]
+            ]
+        ],
+        [
+            ['source', null],
+            ['source', [3, 0, 3]],
+            [
+                ['insert', 3, 0],
+                ['combine', 0, 2],
+                ['combine', 2, 2]
+            ]
+        ]
+    ];
+
+    for (const [[source, mapping], [expectedSource, expectedMapping], operations] of data) {
+        const sourceMap = new TextSourceMap(source, mapping);
+        const expectedSourceMap = new TextSourceMap(expectedSource, expectedMapping);
+        for (const [operation, ...args] of operations) {
+            switch (operation) {
+                case 'combine':
+                    sourceMap.combine(...args);
+                    break;
+                case 'insert':
+                    sourceMap.insert(...args);
+                    break;
+            }
+        }
+        assert.ok(sourceMap.equals(expectedSourceMap));
+    }
+}
+
+
+function main() {
+    testSource();
+    testEquals();
+    testGetSourceLength();
+    testCombineInsert();
+}
+
+
+if (require.main === module) { main(); }