diff --git a/nuxt-i18n.config.js b/nuxt-i18n.config.js
index 1770d703..5ccb0dc4 100644
--- a/nuxt-i18n.config.js
+++ b/nuxt-i18n.config.js
@@ -1,7 +1,7 @@
 const defaultLocale = 'ja'
 
 const options = {
-  strategy: 'no_prefix',
+  strategy: 'prefix_except_default',
   detectBrowserLanguage: false,
   defaultLocale,
   vueI18n: {
@@ -24,7 +24,7 @@ const options = {
       format: 'en',
     },
     {
-      code: 'zh-goyu',
+      code: 'zh-tw',
       displayName: '台灣華語',
       file: 'zh_TW.json',
       format: 'zh-tw',
diff --git a/src/components/EditLessonScreenInner1.vue b/src/components/EditLessonScreenInner1.vue
index 0b05adf7..cdc55bd9 100644
--- a/src/components/EditLessonScreenInner1.vue
+++ b/src/components/EditLessonScreenInner1.vue
@@ -89,7 +89,7 @@
         <v-color-picker
           v-if="colorPickerOpen"
           v-model="tempFormData.subjectColor"
-          disabled
+          hide-sliders
           hide-canvas
           hide-inputs
           hide-mode-switch
diff --git a/src/components/LessonSummaryCard.vue b/src/components/LessonSummaryCard.vue
index 7050b15b..ae27cab3 100644
--- a/src/components/LessonSummaryCard.vue
+++ b/src/components/LessonSummaryCard.vue
@@ -83,7 +83,7 @@ export default Vue.extend({
   methods: {
     toLessonDetail() {
       const lesson = this.lesson as LessonWithId
-      this.$router.push('/lesson/?lessonId=' + lesson.id)
+      this.$router.push(this.localePath('/lesson/?lessonId=' + lesson.id))
     },
   },
 })
diff --git a/src/layouts/background.vue b/src/layouts/background.vue
index ff1ce547..63ac01c6 100644
--- a/src/layouts/background.vue
+++ b/src/layouts/background.vue
@@ -4,7 +4,7 @@
       <div class="loader">Loading</div>
     </v-overlay>
     <v-app-bar fixed app class="bar" elevation="0">
-      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" />
+      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" />
       <header-logo v-else />
       <AppLanguageSelector />
     </v-app-bar>
diff --git a/src/layouts/classes.vue b/src/layouts/classes.vue
index eebcfc45..be58ba27 100644
--- a/src/layouts/classes.vue
+++ b/src/layouts/classes.vue
@@ -64,7 +64,7 @@
       <div class="loader">Loading</div>
     </v-overlay>
     <v-app-bar fixed app class="bar" elevation="0" extension-height="83">
-      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" />
+      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" />
       <header-logo v-else />
       <AppLanguageSelector />
       <v-spacer />
@@ -153,7 +153,7 @@ export default Vue.extend({
     async clickLogout() {
       await vxm.user.logout()
       await vxm.app.resetDate()
-      await this.$router.push('/')
+      await this.$router.push(this.localePath('/'))
     },
   },
 })
diff --git a/src/layouts/default.vue b/src/layouts/default.vue
index 51d23adf..d3305336 100644
--- a/src/layouts/default.vue
+++ b/src/layouts/default.vue
@@ -4,7 +4,7 @@
       <div class="loader">Loading</div>
     </v-overlay>
     <v-app-bar fixed app class="bar" elevation="0">
-      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" />
+      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" />
       <header-logo v-else />
       <AppLanguageSelector />
     </v-app-bar>
diff --git a/src/layouts/error.vue b/src/layouts/error.vue
index 9ffdda2b..5da22ef2 100644
--- a/src/layouts/error.vue
+++ b/src/layouts/error.vue
@@ -6,7 +6,7 @@
     <h1 v-else>
       {{ otherError }}
     </h1>
-    <NuxtLink to="/">Home page</NuxtLink>
+    <NuxtLink :to="localePath('/')">Home page</NuxtLink>
   </v-app>
 </template>
 
diff --git a/src/layouts/lesson.vue b/src/layouts/lesson.vue
index dd6cc58b..c9727ceb 100644
--- a/src/layouts/lesson.vue
+++ b/src/layouts/lesson.vue
@@ -4,7 +4,7 @@
       <div class="loader">Loading</div>
     </v-overlay>
     <v-app-bar fixed app class="bar" elevation="0">
-      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" />
+      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" />
       <header-logo v-else />
       <AppLanguageSelector />
       <v-spacer />
diff --git a/src/layouts/protected.vue b/src/layouts/protected.vue
index 5c7d7514..7977a000 100644
--- a/src/layouts/protected.vue
+++ b/src/layouts/protected.vue
@@ -30,7 +30,7 @@
           ),
           action: () => {
             unloadClassData()
-            $router.push('/user/classlist')
+            $router.push(localePath('/user/classlist'))
             return false
           },
         },
@@ -57,7 +57,7 @@
       <div class="loader">Loading</div>
     </v-overlay>
     <v-app-bar fixed app class="bar" elevation="0" extension-height="83">
-      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" />
+      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" />
       <header-logo v-else />
       <AppLanguageSelector />
       <v-spacer />
@@ -78,7 +78,7 @@
           outlined
           rounded
           color="#0071C2"
-          @click="$router.push('/user/editUserData')"
+          @click="$router.push(localePath('/user/editUserData'))"
         >
           <v-icon>mdi-cog</v-icon>
         </v-btn>
diff --git a/src/layouts/simple.vue b/src/layouts/simple.vue
index 3e8e2b6b..88e7d9b4 100644
--- a/src/layouts/simple.vue
+++ b/src/layouts/simple.vue
@@ -4,7 +4,7 @@
       <div class="loader">Loading</div>
     </v-overlay>
     <v-app-bar fixed app class="bar" elevation="0">
-      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" />
+      <header-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" />
       <header-logo v-else />
       <AppLanguageSelector />
       <v-spacer />
diff --git a/src/pages/classes/terms.vue b/src/pages/classes/terms.vue
index f60e5f1b..b856b8df 100644
--- a/src/pages/classes/terms.vue
+++ b/src/pages/classes/terms.vue
@@ -1,7 +1,7 @@
 <template>
   <div class="MainPage">
     <div class="Logo-outer">
-      <prj-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" class="Logo" />
+      <prj-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" class="Logo" />
       <prj-logo v-else class="Logo" />
     </div>
     <div class="PolicyText-outer">
@@ -34,7 +34,7 @@
       class="Button"
       theme="border"
       :text="$t('common.agree_terms.buttons.disagree')"
-      @click="$router.push('/')"
+      @click="$router.push(localePath('/'))"
     />
   </div>
 </template>
diff --git a/src/pages/edit/index.vue b/src/pages/edit/index.vue
index 3edb99a3..4320152f 100644
--- a/src/pages/edit/index.vue
+++ b/src/pages/edit/index.vue
@@ -34,7 +34,7 @@
         </li>
 
         <li>
-          <nuxt-link class="white--text" to="terms">
+          <nuxt-link class="white--text" :to="localePath('/terms')">
             {{ $t('common.footer.terms') }}
           </nuxt-link>
         </li>
@@ -67,7 +67,7 @@
         </li>
 
         <li>
-          <nuxt-link class="white--text" to="terms">
+          <nuxt-link class="white--text" :to="localePath('/terms')">
             {{ $t('common.footer.terms') }}
           </nuxt-link>
         </li>
@@ -100,7 +100,7 @@
         </li>
 
         <li>
-          <nuxt-link class="white--text" to="terms">
+          <nuxt-link class="white--text" :to="localePath('/terms')">
             {{ $t('common.footer.terms') }}
           </nuxt-link>
         </li>
diff --git a/src/pages/index.vue b/src/pages/index.vue
index c436446b..4a2d9532 100644
--- a/src/pages/index.vue
+++ b/src/pages/index.vue
@@ -42,13 +42,13 @@
             v-if="isLoggedIn"
             :text="$t('pages.index.teachers.buttons.registerLessons')"
             class="registerButton"
-            @click="$router.push('/user/classlist')"
+            @click="$router.push(localePath('/user/classlist'))"
           />
           <base-action-button
             v-else
             :text="$t('pages.index.teachers.buttons.signup')"
             class="registerButton"
-            @click="$router.push('/user/agree')"
+            @click="$router.push(localePath('/user/agree'))"
           />
 
           <base-action-button
@@ -56,14 +56,14 @@
             :text="$t('pages.index.teachers.buttons.logout')"
             class="loginButton"
             theme="secondary"
-            @click="$router.push('/user/logout')"
+            @click="$router.push(localePath('/user/logout'))"
           />
           <base-action-button
             v-else
             :text="$t('pages.index.teachers.buttons.login')"
             class="loginButton"
             theme="secondary"
-            @click="$router.push('/user/login')"
+            @click="$router.push(localePath('/user/login'))"
           />
 
           <v-footer color="#004170" padless>
@@ -90,7 +90,7 @@
               </li>
 
               <li>
-                <nuxt-link class="white--text" to="terms">
+                <nuxt-link class="white--text" :to="localePath('/terms')">
                   {{ $t('common.footer.terms') }}
                 </nuxt-link>
               </li>
@@ -167,7 +167,7 @@ export default Vue.extend({
             classId: this.classId,
             className,
           })
-          await this.$router.push('/classes')
+          await this.$router.push(this.localePath('/classes'))
         }
       } catch {
         this.loading = false
diff --git a/src/pages/terms.vue b/src/pages/terms.vue
index 6358924c..64132478 100644
--- a/src/pages/terms.vue
+++ b/src/pages/terms.vue
@@ -1,7 +1,7 @@
 <template>
   <div class="MainPage">
     <div class="Logo-outer">
-      <prj-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" class="Logo" />
+      <prj-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" class="Logo" />
       <prj-logo v-else class="Logo" />
     </div>
     <div class="PolicyText-outer">
diff --git a/src/pages/user/agree.vue b/src/pages/user/agree.vue
index 6ecfc0d7..34e85e75 100644
--- a/src/pages/user/agree.vue
+++ b/src/pages/user/agree.vue
@@ -1,7 +1,7 @@
 <template>
   <div class="MainPage">
     <div class="Logo-outer">
-      <prj-logo-zhtw v-if="$root.$i18n.locale === 'zh-goyu'" class="Logo" />
+      <prj-logo-zhtw v-if="$root.$i18n.locale === 'zh-tw'" class="Logo" />
       <prj-logo v-else class="Logo" />
     </div>
     <div class="PolicyText-outer">
@@ -302,13 +302,13 @@
       class="Button"
       theme="primary"
       text="登録へ進む"
-      @click="$router.push('/user/signup')"
+      @click="$router.push(localePath('/user/signup'))"
     />
     <base-action-button
       class="Button"
       theme="border"
       text="同意しない"
-      @click="$router.push('/')"
+      @click="$router.push(localePath('/'))"
     />
   </div>
 </template>
diff --git a/src/pages/user/classlist.vue b/src/pages/user/classlist.vue
index b5de97b6..c56a2435 100644
--- a/src/pages/user/classlist.vue
+++ b/src/pages/user/classlist.vue
@@ -42,7 +42,7 @@
       <base-action-button
         :text="$t('pages.user_classlist.add_class')"
         theme="secondary"
-        @click="$router.push('/user/registerClass')"
+        @click="$router.push(localePath('/user/registerClass'))"
       />
     </template>
   </base-bottom-sheet-layer>
@@ -113,7 +113,7 @@ export default Vue.extend({
       this.loading = true
       try {
         await vxm.classData.loadClassData(this.selectedClassId)
-        await this.$router.push('/edit')
+        await this.$router.push(this.localePath('/edit'))
       } catch {
         this.loading = false
       }
diff --git a/src/pages/user/editUserData.vue b/src/pages/user/editUserData.vue
index 0d49071c..abdec7e8 100644
--- a/src/pages/user/editUserData.vue
+++ b/src/pages/user/editUserData.vue
@@ -15,7 +15,7 @@
               color="white"
               height="auto"
               class="ToEditNavButton"
-              @click="$router.push('/user/editUserName')"
+              @click="$router.push(localePath('/user/editUserName'))"
             >
               {{ name }}
               <v-icon right color="#0071C2"> mdi-chevron-right </v-icon>
@@ -30,7 +30,7 @@
               color="white"
               height="auto"
               class="ToEditNavButton"
-              @click="$router.push('/user/editUserEmail')"
+              @click="$router.push(localePath('/user/editUserEmail'))"
             >
               {{ email }}
               <v-icon right color="#0071C2"> mdi-chevron-right </v-icon>
@@ -45,7 +45,7 @@
               color="white"
               height="auto"
               class="ToEditNavButton"
-              @click="$router.push('/user/editUserPassword')"
+              @click="$router.push(localePath('/user/editUserPassword'))"
             >
               ********
               <v-icon right color="#0071C2"> mdi-chevron-right </v-icon>
@@ -59,7 +59,7 @@
             theme="transparent"
             :text="$t('common.general.buttons.cancel')"
             class="SignUp-Button"
-            @click="$router.push('/edit')"
+            @click="$router.push(localePath('/edit'))"
           />
           <v-btn
             :disabled="loading"
@@ -125,7 +125,7 @@ export default Vue.extend<Data, Methods, Computed, unknown>({
       try {
         await vxm.user.logout()
         await vxm.app.resetDate()
-        await this.$router.push('/')
+        await this.$router.push(this.localePath('/'))
       } catch {
         this.error = true
       }
diff --git a/src/pages/user/editUserEmail.vue b/src/pages/user/editUserEmail.vue
index 7bbbe9b5..5d8438af 100644
--- a/src/pages/user/editUserEmail.vue
+++ b/src/pages/user/editUserEmail.vue
@@ -31,7 +31,7 @@
             theme="transparent"
             :text="$t('common.general.buttons.cancel')"
             class="SignUp-Button"
-            @click="$router.push('/user/editUserData')"
+            @click="$router.push(localePath('/user/editUserData'))"
           />
           <base-action-button
             theme="primary"
@@ -100,7 +100,7 @@ export default Vue.extend<Data, Methods, Computed, unknown>({
             await Auth.updateUserAttributes(user, {
               email: this.email,
             })
-            await this.$router.push('/user/verifyNewEmail')
+            await this.$router.push(this.localePath('/user/verifyNewEmail'))
           } catch {
             this.error = true
             this.loading = false
diff --git a/src/pages/user/editUserName.vue b/src/pages/user/editUserName.vue
index 36807a08..ebb514df 100644
--- a/src/pages/user/editUserName.vue
+++ b/src/pages/user/editUserName.vue
@@ -30,7 +30,7 @@
             theme="transparent"
             :text="$t('common.general.buttons.cancel')"
             class="SignUp-Button"
-            @click="$router.push('/user/editUserData')"
+            @click="$router.push(localePath('/user/editUserData'))"
           />
           <base-action-button
             theme="primary"
@@ -99,7 +99,7 @@ export default Vue.extend<Data, Methods, Computed, unknown>({
             await Auth.updateUserAttributes(user, {
               name: this.name,
             })
-            await this.$router.push('/user/editUserData')
+            await this.$router.push(this.localePath('/user/editUserData'))
           } catch {
             this.error = true
             this.loading = false
diff --git a/src/pages/user/editUserPassword.vue b/src/pages/user/editUserPassword.vue
index 52b95d12..c07046ca 100644
--- a/src/pages/user/editUserPassword.vue
+++ b/src/pages/user/editUserPassword.vue
@@ -55,7 +55,7 @@
             theme="transparent"
             :text="$t('common.general.buttons.cancel')"
             class="SignUp-Button"
-            @click="$router.push('/user/editUserData')"
+            @click="$router.push(localePath('/user/editUserData'))"
           />
           <base-action-button
             theme="primary"
@@ -154,7 +154,7 @@ export default Vue.extend<Data, Methods, Computed, unknown>({
               this.currentPassword,
               this.newPassword
             )
-            await this.$router.push('/user/editUserData')
+            await this.$router.push(this.localePath('/user/editUserData'))
           } catch {
             this.error = true
             this.loading = false
diff --git a/src/pages/user/login.vue b/src/pages/user/login.vue
index 53c3a51c..8a2669f0 100644
--- a/src/pages/user/login.vue
+++ b/src/pages/user/login.vue
@@ -48,7 +48,7 @@
             color="#ffffff"
             height="60px"
             text
-            to="/"
+            :to="localePath('/')"
           >
             <span>{{ $t('common.general.buttons.go_back') }}</span>
           </v-btn>
@@ -95,7 +95,7 @@ export default Vue.extend({
       try {
         await Auth.signIn(this.email, this.password)
         // await vxm.user.login()
-        await this.$router.push('/user/classlist')
+        await this.$router.push(this.localePath('/user/classlist'))
       } catch (err) {
         this.loading = false
         this.error = true
diff --git a/src/pages/user/logout.vue b/src/pages/user/logout.vue
index 5cc1a5d2..e1f507cc 100644
--- a/src/pages/user/logout.vue
+++ b/src/pages/user/logout.vue
@@ -35,7 +35,7 @@ export default Vue.extend({
       try {
         await Auth.signOut()
         await vxm.app.resetDate()
-        await this.$router.push('/')
+        await this.$router.push(this.localePath('/'))
       } catch {
         this.loading = false
         this.error = true
diff --git a/src/pages/user/registerClass.vue b/src/pages/user/registerClass.vue
index 37240206..64374f43 100644
--- a/src/pages/user/registerClass.vue
+++ b/src/pages/user/registerClass.vue
@@ -83,7 +83,7 @@ export default Vue.extend({
         })
         .then(() => {
           this.loading = false
-          this.$router.push('/user/registered')
+          this.$router.push(this.localePath('/user/registered'))
         })
         .catch(() => {
           this.error = true
diff --git a/src/pages/user/registered.vue b/src/pages/user/registered.vue
index 43cbe504..efb7fb31 100644
--- a/src/pages/user/registered.vue
+++ b/src/pages/user/registered.vue
@@ -21,7 +21,7 @@
         theme="primary"
         :text="$t('pages.user_registered.buttons.add_or_edit_lessons')"
         class="Registered-Button"
-        @click="$router.push('/edit')"
+        @click="$router.push(localePath('/edit'))"
       />
       <!-- <base-action-button theme="secondary" text="クラスIDを共有する" /> -->
     </template>
diff --git a/src/pages/user/signup.vue b/src/pages/user/signup.vue
index 9e07f34d..2970a494 100644
--- a/src/pages/user/signup.vue
+++ b/src/pages/user/signup.vue
@@ -66,7 +66,7 @@
             theme="transparent"
             :text="$t('common.general.buttons.cancel')"
             class="SignUp-Button"
-            @click="$router.push('/')"
+            @click="$router.push(localePath('/'))"
           />
           <base-action-button
             theme="primary"
@@ -153,10 +153,12 @@ export default Vue.extend({
         .then(() => {
           this.completion = true
           this.loading = false
-          this.$router.push({
-            name: 'user-verify',
-            params: { email: this.email },
-          })
+          this.$router.push(
+            this.localePath({
+              name: 'user-verify',
+              params: { email: this.email },
+            })
+          )
         })
         .catch(() => {
           this.error = true
diff --git a/src/pages/user/verify.vue b/src/pages/user/verify.vue
index bc0a56b5..5911b156 100644
--- a/src/pages/user/verify.vue
+++ b/src/pages/user/verify.vue
@@ -48,7 +48,7 @@
             color="#ffffff"
             height="60px"
             text
-            to="/"
+            :to="localePath('/')"
           >
             <span>{{ $t('common.general.buttons.go_back') }}</span>
           </v-btn>
@@ -93,7 +93,7 @@ export default Vue.extend({
       this.loading = true
       await Auth.confirmSignUp(this.email, this.verification_code)
         .then(() => {
-          this.$router.push('/user/classlist')
+          this.$router.push(this.localePath('/user/classlist'))
         })
         .catch(() => {
           this.loading = false
diff --git a/src/pages/user/verifyNewEmail.vue b/src/pages/user/verifyNewEmail.vue
index 942a9980..35c4e2e2 100644
--- a/src/pages/user/verifyNewEmail.vue
+++ b/src/pages/user/verifyNewEmail.vue
@@ -48,7 +48,7 @@
             color="#ffffff"
             height="60px"
             text
-            to="/"
+            :to="localePath('/')"
           >
             <span>{{ $t('common.general.buttons.go_back') }}</span>
           </v-btn>
@@ -97,7 +97,7 @@ export default Vue.extend({
         this.verification_code
       )
         .then(() => {
-          this.$router.push('/user/editUserData')
+          this.$router.push(this.localePath('/user/editUserData'))
         })
         .catch(() => {
           this.loading = false