diff --git a/assets/javascripts/lib/i18n.coffee b/assets/javascripts/lib/i18n.coffee
index 52c8fc4d..8c2e1410 100644
--- a/assets/javascripts/lib/i18n.coffee
+++ b/assets/javascripts/lib/i18n.coffee
@@ -1,6 +1,6 @@
 class @I18n
   default: 'en'
-  constructor: (@langs = [@default]) ->
+  constructor: (@langs = [@default], @phrases) ->
 
   _: (obj, substitution) =>
     if typeof obj is 'object' or typeof obj is 'function'
@@ -8,14 +8,18 @@ class @I18n
     else
       obj
 
-  get_lang: (obj) ->
+  __: (key) =>
+    lang = @get_lang @phrases, (lang) => @phrases[lang]?[key]
+    @phrases[lang]?[key] ? ''
+
+  get_lang: (obj, test = (lang) -> obj[lang]) ->
     for lang in @langs
       # eg. en-US
-      return lang if obj[lang]
+      return lang if test lang
 
       lang = lang.replace /_\w+$/, ''
       # eg. en
-      return lang if obj[lang]
+      return lang if test lang
 
     @default
 
@@ -26,5 +30,13 @@ class @I18n
         str = str.replace("{#{key}}", substitution[key])
     str
 
-@i18n = new I18n navigator.languages
+@i18n = new I18n navigator.languages,
+  en:
+    enable: "Enable"
+    documentation: "Documentation"
+  ja:
+    enable: "有効"
+    documentation: "ドキュメンテーション"
+
 @_ = @i18n._
+@__ = @i18n.__
diff --git a/assets/javascripts/templates/notif_tmpl.coffee b/assets/javascripts/templates/notif_tmpl.coffee
index 2313b81d..01ccd9f5 100644
--- a/assets/javascripts/templates/notif_tmpl.coffee
+++ b/assets/javascripts/templates/notif_tmpl.coffee
@@ -82,7 +82,7 @@ app.templates.notifUpdates = (docs, disabledDocs) ->
     for doc in disabledDocs
       html += "<li>#{doc.name}"
       html += " <code>&rarr;</code> #{doc.release}" if doc.release
-      html += """<span class="_notif-info"><a href="/settings">Enable</a></span>"""
+      html += """<span class="_notif-info"><a href="/settings">#{__ 'enable'}</a></span>"""
     html += '</ul></div>'
 
   notif 'Updates', "#{html}</div>"
diff --git a/assets/javascripts/templates/pages/about_tmpl.coffee b/assets/javascripts/templates/pages/about_tmpl.coffee
index 30c25999..6c019352 100644
--- a/assets/javascripts/templates/pages/about_tmpl.coffee
+++ b/assets/javascripts/templates/pages/about_tmpl.coffee
@@ -68,7 +68,7 @@ app.templates.aboutPage =
     <div class="_table">
       <table class="_credits">
         <tr>
-          <th>Documentation
+          <th>#{__ 'documentation'}
           <th>Copyright
           <th>License
         #{credit_table}
@@ -148,7 +148,7 @@ app.templates.aboutPage =
     <div class="_table">
       <table class="_credits">
         <tr>
-          <th>Documentation
+          <th>#{__ 'documentation'}
           <th>Copyright
           <th>License
         #{credit_table}
diff --git a/assets/javascripts/templates/pages/offline_tmpl.coffee b/assets/javascripts/templates/pages/offline_tmpl.coffee
index a9a3c21c..706dba89 100644
--- a/assets/javascripts/templates/pages/offline_tmpl.coffee
+++ b/assets/javascripts/templates/pages/offline_tmpl.coffee
@@ -13,7 +13,7 @@ app.templates.offlinePage = (docs) -> """
   <div class="_table">
     <table class="_docs">
       <tr>
-        <th>Documentation</th>
+        <th>#{__ 'documentation'}</th>
         <th class="_docs-size">Size</th>
         <th>Status</th>
         <th>Action</th>
diff --git a/assets/javascripts/templates/sidebar_tmpl.coffee b/assets/javascripts/templates/sidebar_tmpl.coffee
index aa095505..4ee2f99e 100644
--- a/assets/javascripts/templates/sidebar_tmpl.coffee
+++ b/assets/javascripts/templates/sidebar_tmpl.coffee
@@ -7,7 +7,7 @@ templates.sidebarDoc = (doc, options = {}) ->
   link += if options.disabled then '_list-disabled' else '_list-dir'
   link += """" data-slug="#{doc.slug}" title="#{doc.fullName}" tabindex="-1">"""
   if options.disabled
-    link += """<span class="_list-enable" data-enable="#{doc.slug}">Enable</span>"""
+    link += """<span class="_list-enable" data-enable="#{doc.slug}">#{__ 'enable'}</span>"""
   else
     link += arrow
   link += """<span class="_list-count">#{doc.release}</span>""" if doc.release
@@ -23,7 +23,7 @@ templates.sidebarEntry = (entry) ->
 
 templates.sidebarResult = (entry) ->
   addons = if entry.isIndex() and app.disabledDocs.contains(entry.doc)
-    """<span class="_list-enable" data-enable="#{entry.doc.slug}">#{_ en: "Enable", ja: "有効"}</span>"""
+    """<span class="_list-enable" data-enable="#{entry.doc.slug}">#{__ 'enable'}</span>"""
   else
     """<span class="_list-reveal" data-reset-list title="Reveal in list"></span>"""
   addons += """<span class="_list-count">#{entry.doc.short_version}</span>""" if entry.doc.version and not entry.isIndex()
@@ -66,9 +66,7 @@ templates.sidebarDisabledList = (html) ->
 templates.sidebarDisabledVersionedDoc = (doc, versions) ->
   """<a class="_list-item _list-dir _icon-#{doc.icon} _list-disabled" data-slug="#{doc.slug_without_version}" tabindex="-1">#{arrow}#{doc.name}</a><div class="_list _list-sub">#{versions}</div>"""
 
-templates.docPickerHeader =
-  en: """<div class="_list-picker-head"><span>Documentation</span> <span>Enable</span></div>"""
-  ja: """<div class="_list-picker-head"><span>ドキュメント</span> <span>Enable</span></div>"""
+templates.docPickerHeader = -> """<div class="_list-picker-head"><span>#{__ 'documentation'}</span> <span>#{__ 'enable'}</span></div>"""
 
 templates.docPickerNote =
   en: """