diff --git a/gui/scripts/i18n-backend.ts b/gui/scripts/i18n-backend.ts
index 4471c51..d6584a2 100644
--- a/gui/scripts/i18n-backend.ts
+++ b/gui/scripts/i18n-backend.ts
@@ -10,7 +10,7 @@ const keys: Set<string> = new Set();
 
 async function updateFile() {
   delayId = null;
-  for (const lng of ["en", "zh-CN"]) {
+  for (const lng of ["en", 'ja', "zh-CN"]) {
     const translationPath = path.join(
       __dirname,
       `../src/i18n/translation/${lng}.json`,
diff --git a/gui/src-tauri/src/main.rs b/gui/src-tauri/src/main.rs
index 22e50d3..9424797 100644
--- a/gui/src-tauri/src/main.rs
+++ b/gui/src-tauri/src/main.rs
@@ -36,11 +36,12 @@ detectAndInject();
 "#;
 
 #[tauri::command]
-async fn open_splatnet(app: tauri::AppHandle, gtoken: String) -> Option<()> {
+async fn open_splatnet(app: tauri::AppHandle, gtoken: String, lang: Option<String>) -> Option<()> {
+    let ui_lang = lang.unwrap_or_else(|| "en-US".to_string());
     let _window = WindowBuilder::new(
         &app,
         "splatnet3",
-        tauri::WindowUrl::App("https://api.lp1.av5ja.srv.nintendo.net/".into()),
+        tauri::WindowUrl::App(format!("https://api.lp1.av5ja.srv.nintendo.net/?lang={ui_lang}").into()),
     )
     .title("Splatnet3")
     .center()
diff --git a/gui/src/components/OpenSplatnet.tsx b/gui/src/components/OpenSplatnet.tsx
index 89c999a..5155e0e 100644
--- a/gui/src/components/OpenSplatnet.tsx
+++ b/gui/src/components/OpenSplatnet.tsx
@@ -35,6 +35,7 @@ export const OpenSplatnet: React.FC<OpenSplatnetProps> = ({ children }) => {
       const gtoken = newState.loginState?.gToken;
       await invoke('open_splatnet', {
         gtoken,
+        lang: result.profile.state.userLang,
       });
     } catch (e) {
       setError(e);
diff --git a/gui/src/i18n/config.ts b/gui/src/i18n/config.ts
index e574100..ea430c1 100644
--- a/gui/src/i18n/config.ts
+++ b/gui/src/i18n/config.ts
@@ -3,6 +3,7 @@ import LanguageDetector from 'i18next-browser-languagedetector';
 import { initReactI18next } from 'react-i18next';
 import en from './translation/en.json';
 import zhCN from './translation/zh-CN.json';
+import ja from './translation/ja.json';
 import HttpBackend from 'i18next-http-backend'
 
 export const resources = {
@@ -11,6 +12,9 @@ export const resources = {
   },
   'zh-CN': {
     translation: zhCN,
+  },
+  ja: {
+    translation: ja,
   }
 };
 
@@ -25,5 +29,6 @@ if (import.meta.env.DEV) {
 instance.init({
   debug: import.meta.env.DEV,
   resources,
+  fallbackLng: 'en',
   // saveMissing: true,
 });
diff --git a/gui/src/i18n/translation/en.json b/gui/src/i18n/translation/en.json
index 9e26dfe..a0cabf2 100644
--- a/gui/src/i18n/translation/en.json
+++ b/gui/src/i18n/translation/en.json
@@ -1 +1,23 @@
-{}
\ No newline at end of file
+{
+  "保存": "Save",
+  "查看API密钥": "View API Key",
+  "打开 stat.ink": "Open stat.ink",
+  "打开鱿鱼圈3": "Open Splatnet3",
+  "导出": "Export",
+  "导出打工数据": "Export Salmon Run",
+  "导出对战数据": "Export VS",
+  "欢迎! 请点击\"导出\"按钮开始使用.": "Welcome! Please click \"Export\" button to start using.",
+  "界面语言": "Interface Language",
+  "没有更改": "No changes made",
+  "密钥的长度应该为{{length}}, 请检查": "The length of the key should be {{length}}, please check",
+  "前往 stat.ink": "Go to stat.ink",
+  "请从stat.ink中获取API密钥": "Please obtain the API key from stat.ink",
+  "请点击右上角的登录填入": "Please click the top right corner to log in",
+  "请先在设置中完成Nintendo Account登录和stat.ink的API密钥": "Please complete Nintendo Account login and stat.ink API key setup in settings first",
+  "设置": "Settings",
+  "网页登录": "Web Login",
+  "鱿鱼圈3语言偏好": "Splatnet3 Language",
+  "重置": "Reset",
+  "Nintendo Account 会话令牌": "Nintendo Account Session Token",
+  "stat.ink API密钥": "stat.ink API Key"
+}
\ No newline at end of file
diff --git a/gui/src/i18n/translation/ja.json b/gui/src/i18n/translation/ja.json
new file mode 100644
index 0000000..fbd8142
--- /dev/null
+++ b/gui/src/i18n/translation/ja.json
@@ -0,0 +1,23 @@
+{
+  "保存": "保存",
+  "查看API密钥": "APIキーを表示する",
+  "打开 stat.ink": "stat.inkを開く",
+  "打开鱿鱼圈3": "イカリング3を開く",
+  "导出": "エクスポートする",
+  "导出打工数据": "勤務データをエクスポートする",
+  "导出对战数据": "対戦データをエクスポートする",
+  "欢迎! 请点击\"导出\"按钮开始使用.": "ようこそ！「エクスポート」ボタンをクリックして使い始めてください。",
+  "界面语言": "インターフェース言語",
+  "没有更改": "変更はありません",
+  "密钥的长度应该为{{length}}, 请检查": "キーの長さは{{length}}でなければなりません。確認してください。",
+  "前往 stat.ink": "stat.inkに移動する",
+  "请从stat.ink中获取API密钥": "stat.inkからAPIキーを取得してください",
+  "请点击右上角的登录填入": "右上隅のログインをクリックして入力してください",
+  "请先在设置中完成Nintendo Account登录和stat.ink的API密钥": "Nintendoアカウントのログインとstat.inkのAPIキー設定を先に設定してください",
+  "设置": "設定",
+  "网页登录": "ウェブサイトにログインする",
+  "鱿鱼圈3语言偏好": "イカリング3言語設定",
+  "重置": "リセット",
+  "Nintendo Account 会话令牌": "Nintendo Accountセッショントークン",
+  "stat.ink API密钥": "stat.ink APIキー"
+}
\ No newline at end of file
diff --git a/gui/src/i18n/translation/zh-CN.json b/gui/src/i18n/translation/zh-CN.json
index 9e26dfe..cb57b2b 100644
--- a/gui/src/i18n/translation/zh-CN.json
+++ b/gui/src/i18n/translation/zh-CN.json
@@ -1 +1,23 @@
-{}
\ No newline at end of file
+{
+  "保存": "保存",
+  "查看API密钥": "查看API密钥",
+  "打开 stat.ink": "打开 stat.ink",
+  "打开鱿鱼圈3": "打开鱿鱼圈3",
+  "导出": "导出",
+  "导出打工数据": "导出打工数据",
+  "导出对战数据": "导出对战数据",
+  "欢迎! 请点击\"导出\"按钮开始使用.": "欢迎! 请点击\"导出\"按钮开始使用.",
+  "界面语言": "界面语言",
+  "没有更改": "没有更改",
+  "密钥的长度应该为{{length}}, 请检查": "密钥的长度应该为{{length}}, 请检查",
+  "前往 stat.ink": "前往 stat.ink",
+  "请从stat.ink中获取API密钥": "请从stat.ink中获取API密钥",
+  "请点击右上角的登录填入": "请点击右上角的登录填入",
+  "请先在设置中完成Nintendo Account登录和stat.ink的API密钥": "请先在设置中完成Nintendo Account登录和stat.ink的API密钥",
+  "设置": "设置",
+  "网页登录": "网页登录",
+  "鱿鱼圈3语言偏好": "鱿鱼圈3语言偏好",
+  "重置": "重置",
+  "Nintendo Account 会话令牌": "Nintendo Account 会话令牌",
+  "stat.ink API密钥": "stat.ink API密钥"
+}
\ No newline at end of file
diff --git a/gui/src/pages/Settings.tsx b/gui/src/pages/Settings.tsx
index 379e656..2c94cbe 100644
--- a/gui/src/pages/Settings.tsx
+++ b/gui/src/pages/Settings.tsx
@@ -27,12 +27,34 @@ type FormData = {
   profile: Profile,
 }
 
+const SPLATNET3_LANGS = {
+  "de-DE": "German",
+  "en-GB": "English (UK/Australia)",
+  "en-US": "English (US)",
+  "es-ES": "Spanish (Spain)",
+  "es-MX": "Spanish (Latin America)",
+  "fr-CA": "French (Canada)",
+  "fr-FR": "French (France)",
+  "it-IT": "Italian",
+  "ja-JP": "Japanese",
+  "ko-KR": "Korean",
+  "nl-NL": "Dutch",
+  "ru-RU": "Russian",
+  "zh-CN": "Chinese (China)",
+  "zh-TW": "Chinese (Taiwan)"
+}
+const UI_LANGS = {
+  "en": "English",
+  "zh-CN": "简体中文",
+  "ja": "日本語",
+};
+
 const Form: React.FC<{
   oldValue: FormData,
   onSaved?: () => void,
 }> = ({ oldValue, onSaved }) => {
   const { login } = useLogin();
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
   const [value, setValue] = useState(oldValue);
   const { subField } = useSubField({ value, onChange: setValue });
 
@@ -40,6 +62,7 @@ const Form: React.FC<{
 
   const sessionToken = subField('profile.state.loginState.sessionToken')
   const statInkApiKey = subField('profile.state.statInkApiKey')
+  const splatnet3Lang = subField('profile.state.userLang')
 
   const [onSave, { loading, error }] = usePromiseLazy(async () => {
     await setProfile(0, value.profile);
@@ -100,6 +123,28 @@ const Form: React.FC<{
           />
         </div>
       </div>
+      <div className="form-control w-full max-w-md mb-4">
+        <label className="label">
+          <span className="label-text">{t('鱿鱼圈3语言偏好')}</span>
+        </label>
+        <select className="select w-full" value={splatnet3Lang.value} onChange={
+          e => splatnet3Lang.onChange(e.target.value)
+        }>
+          {Object.entries(SPLATNET3_LANGS).map(([key, value]) => <option key={key} value={key}>{value} ({key})</option>)}
+        </select>
+      </div>
+      <div className="form-control w-full max-w-md mb-4">
+        <label className="label">
+          <span className="label-text">{t('界面语言')}</span>
+        </label>
+        <select className="select w-full" value={i18n.language} onChange={
+          e => {
+            i18n.changeLanguage(e.target.value);
+          }
+        }>
+          {Object.entries(UI_LANGS).map(([key, value]) => <option key={key} value={key}>{value} ({key})</option>)}
+        </select>
+      </div>
     </div>
     <ErrorContent error={error} />
     <div className='flex gap-4 max-w-md justify-between flex-auto-all'>