diff --git a/LifeOS/install/LIFEOS/TOOLS/LifeosConfig.ts b/LifeOS/install/LIFEOS/TOOLS/LifeosConfig.ts
index ca5d03d9b9..6949b570fa 100644
--- a/LifeOS/install/LIFEOS/TOOLS/LifeosConfig.ts
+++ b/LifeOS/install/LIFEOS/TOOLS/LifeosConfig.ts
@@ -38,6 +38,10 @@ export interface LifeosPrincipal {
   timezone: string;
   hometown?: string;
   voiceCloneId?: string;
+  // ISO 639-1 code (e.g. "ja"). Optional — most consumers (hooks/lib/locale.ts,
+  // hooks/lib/work-strings.ts) fall back to WORK.ISSUE_LANGUAGE or "en" when
+  // this is unset, so existing TOML files need no edit.
+  language?: string;
 }
 
 export interface LifeosVoiceSettings {
@@ -169,6 +173,7 @@ function validateAndNormalize(raw: unknown, path: string): LifeosConfig {
       timezone: principal.timezone,
       hometown: principal.hometown,
       voiceCloneId: principal.voice_clone_id ?? principal.voiceCloneId,
+      language: principal.language,
     },
     da: {
       name: da.name,
diff --git a/LifeOS/install/hooks/SatisfactionCapture.hook.ts b/LifeOS/install/hooks/SatisfactionCapture.hook.ts
index 6b6722c78d..5a7596e366 100755
--- a/LifeOS/install/hooks/SatisfactionCapture.hook.ts
+++ b/LifeOS/install/hooks/SatisfactionCapture.hook.ts
@@ -38,6 +38,7 @@ import { getLearningCategory } from './lib/learning-utils';
 import { getISOTimestamp, getPSTComponents } from './lib/time';
 import { captureFailure } from '../LIFEOS/TOOLS/FailureCapture';
 import { addRatingPulse } from './lib/isa-utils';
+import { resolveLang, tList } from './lib/locale';
 
 // Normalize env path vars that Claude Code injects without shell expansion (LifeOS#1404)
 for (const k of ["LIFEOS_DIR", "LIFEOS_CONFIG_DIR", "PROJECTS_DIR"]) {
@@ -160,6 +161,23 @@ const POSITIVE_PHRASES = new Set([
   'love it', 'nailed it', 'looks great', 'looks good', 'thats great', 'that works',
 ]);
 
+// Locale vocabulary is UNIONED onto the English sets above, never substituted
+// for them — an English "perfect" stays praise under any locale (see
+// hooks/lib/locale.ts's tList() doc comment for why union, not override, is
+// the correct semantics here). RATING_LANG resolves once per hook invocation;
+// tList() returns [] for "en" or an unset/missing/malformed locale bundle, so
+// with no locale configured EFFECTIVE_* is the exact same Set reference as
+// the English one — locale-unset output is provably unchanged.
+const RATING_LANG = resolveLang();
+const LOCALE_PRAISE_WORDS = tList(RATING_LANG, 'praise.words');
+const LOCALE_PRAISE_PHRASES = tList(RATING_LANG, 'praise.phrases');
+const EFFECTIVE_PRAISE_WORDS = LOCALE_PRAISE_WORDS.length
+  ? new Set([...POSITIVE_PRAISE_WORDS, ...LOCALE_PRAISE_WORDS])
+  : POSITIVE_PRAISE_WORDS;
+const EFFECTIVE_PRAISE_PHRASES = LOCALE_PRAISE_PHRASES.length
+  ? new Set([...POSITIVE_PHRASES, ...LOCALE_PRAISE_PHRASES])
+  : POSITIVE_PHRASES;
+
 // ── System Text Detection ──
 
 const SYSTEM_TEXT_PATTERNS = [
@@ -323,11 +341,13 @@ async function main() {
     }
 
     // ── FAST PATH: Positive praise ──
-    const normalizedPrompt = prompt.trim().toLowerCase().replace(/[.!?,'"]/g, '');
+    // Full-width CJK punctuation ("完璧！" → "完璧") joins the ASCII set below —
+    // English prompts never contain these characters, so this is a no-op for them.
+    const normalizedPrompt = prompt.trim().toLowerCase().replace(/[.!?,'"。、！？…「」]/g, '');
     const promptWords = normalizedPrompt.split(/\s+/);
     if (promptWords.length <= 2) {
-      if (POSITIVE_PRAISE_WORDS.has(normalizedPrompt) || POSITIVE_PHRASES.has(normalizedPrompt)
-          || (promptWords.length === 2 && promptWords.every(w => POSITIVE_PRAISE_WORDS.has(w)))) {
+      if (EFFECTIVE_PRAISE_WORDS.has(normalizedPrompt) || EFFECTIVE_PRAISE_PHRASES.has(normalizedPrompt)
+          || (promptWords.length === 2 && promptWords.every(w => EFFECTIVE_PRAISE_WORDS.has(w)))) {
         console.error(`[SatisfactionCapture] Positive praise fast-path: "${prompt.trim()}" → rating 8`);
         const cachedResponse = getLastResponse();
         writeRating({
diff --git a/LifeOS/install/hooks/lib/locale.ts b/LifeOS/install/hooks/lib/locale.ts
new file mode 100644
index 0000000000..4401479d57
--- /dev/null
+++ b/LifeOS/install/hooks/lib/locale.ts
@@ -0,0 +1,144 @@
+/**
+ * locale.ts — Generic locale-bundle lookup, generalized out of work-strings.ts's
+ * Work-System-specific design contract (LifeOS#1695) so any surface can adopt
+ * per-key translation without inventing its own loader.
+ *
+ * Two lookup shapes, because prose and vocabulary need opposite fallback
+ * semantics:
+ *
+ *   - `t()` is OVERRIDE. A locale bundle replaces the caller's default string
+ *     for a key it translates; the caller supplies the default (there is no
+ *     baked-in EN dictionary here — that's owned per-surface, same as
+ *     work-strings.ts owns its own `EN` for Work System issue bodies).
+ *   - `tList()` is UNION. A locale bundle's array values are ADDED to the
+ *     caller's own list, never replacing it — a Japanese locale should still
+ *     recognize "perfect" as praise, not lose English vocabulary by opting
+ *     into `ja`. This is what makes "locale unset → byte-identical output"
+ *     provable by construction: with no bundle, `tList()` returns `[]` and
+ *     the caller's own English list is untouched.
+ *
+ * `resolveLang()` priority: explicit arg > LIFEOS_CONFIG.toml [principal].language
+ * > WORK.ISSUE_LANGUAGE (USER/WORK/config.yaml — the Work System's existing
+ * locale switch, read independently here so a principal who already set it
+ * for issue bodies gets it for free elsewhere) > "en". Every step is
+ * try/catch-guarded; a missing or malformed config file falls through to the
+ * next step rather than throwing — same fail-open contract work-strings.ts
+ * uses for locale bundles themselves.
+ *
+ * Locale files live at `<userDir>/CONFIG/locales/<lang>.json` (same file
+ * work-strings.ts reads), resolved via `paiUserDir()` — never a literal
+ * `LIFEOS/USER/...` string (LIFEOS/DOCUMENTATION/SystemUserBoundary.md §
+ * INTERFACE).
+ */
+
+import { existsSync, readFileSync } from "fs";
+import { homedir } from "os";
+import { join } from "path";
+import { loadLifeosConfig, paiUserDir } from "../../LIFEOS/TOOLS/LifeosConfig";
+
+const LIFEOS_DIR = process.env.LIFEOS_DIR || join(process.env.HOME || homedir(), ".claude", "LIFEOS");
+const WORK_CONFIG_YAML_PATH = join(LIFEOS_DIR, "USER", "WORK", "config.yaml");
+
+/**
+ * Reads `WORK.ISSUE_LANGUAGE` directly from config.yaml. Deliberately not
+ * shared with hooks/lib/work-config.ts's `loadIssueLanguage()` (which parses
+ * the same key) — that loader is scoped to the Work System's own config
+ * object and isn't exported; duplicating one regex here keeps this module
+ * standalone rather than reaching into Work System internals for one value.
+ */
+function loadWorkIssueLanguage(): string | null {
+  if (!existsSync(WORK_CONFIG_YAML_PATH)) return null;
+  try {
+    const yaml = readFileSync(WORK_CONFIG_YAML_PATH, "utf-8");
+    const m = yaml.match(/^\s*ISSUE_LANGUAGE:\s*(.+?)\s*$/m);
+    if (!m) return null;
+    const val = m[1].replace(/^["']|["']$/g, "").trim();
+    return val || null;
+  } catch {
+    return null;
+  }
+}
+
+export function resolveLang(explicit?: string): string {
+  if (explicit) return explicit;
+  try {
+    const cfgLang = loadLifeosConfig().principal.language;
+    if (cfgLang) return cfgLang;
+  } catch {
+    // Missing/invalid LIFEOS_CONFIG.toml — fall through to WORK.ISSUE_LANGUAGE / en.
+  }
+  return loadWorkIssueLanguage() ?? "en";
+}
+
+// One-entry-per-lang cache for the current process (hooks are short-lived,
+// so this only saves repeat lookups within a single invocation).
+const bundleCache = new Map<string, Record<string, unknown> | null>();
+
+function loadLocaleBundle(lang: string): Record<string, unknown> | null {
+  if (!lang || lang === "en") return null;
+  if (bundleCache.has(lang)) return bundleCache.get(lang)!;
+  let bundle: Record<string, unknown> | null = null;
+  try {
+    const path = join(paiUserDir(), "CONFIG", "locales", `${lang}.json`);
+    if (existsSync(path)) {
+      const raw = JSON.parse(readFileSync(path, "utf-8"));
+      if (raw && typeof raw === "object" && !Array.isArray(raw)) {
+        bundle = raw as Record<string, unknown>;
+      }
+    }
+  } catch {
+    bundle = null;
+  }
+  bundleCache.set(lang, bundle);
+  return bundle;
+}
+
+function interpolate(template: string, vars: Record<string, string | number>): string {
+  return template.replace(/\{(\w+)\}/g, (whole, name) => {
+    const v = vars[name];
+    return v === undefined ? whole : String(v);
+  });
+}
+
+/**
+ * Resolves `key` for `lang`, falling back to `fallback` for missing locales,
+ * missing files, malformed JSON, a non-string value, or a lang of "en".
+ * Never throws.
+ */
+export function t(
+  lang: string,
+  key: string,
+  fallback: string,
+  vars: Record<string, string | number> = {},
+): string {
+  const bundle = loadLocaleBundle(lang);
+  const raw = bundle && typeof bundle[key] === "string" ? (bundle[key] as string) : fallback;
+  return interpolate(raw, vars);
+}
+
+/**
+ * Returns the locale bundle's array value for `key`, or `[]` if the locale,
+ * file, key, or value shape doesn't resolve. The caller unions this with its
+ * own default list — see the module doc comment for why union (not
+ * override) is the correct semantics for vocabulary lists. Never throws.
+ */
+export function tList(lang: string, key: string): string[] {
+  const bundle = loadLocaleBundle(lang);
+  const v = bundle?.[key];
+  return Array.isArray(v) ? v.filter((x): x is string => typeof x === "string") : [];
+}
+
+// ── CLI smoke ────────────────────────────────────────────────────────────────
+
+if (import.meta.main) {
+  const [lang, key, fallback] = process.argv.slice(2);
+  if (!lang || !key) {
+    console.log("usage: bun locale.ts <lang> <key> [fallback] | bun locale.ts <lang> --list <key>");
+    process.exit(1);
+  }
+  if (key === "--list") {
+    console.log(JSON.stringify(tList(lang, fallback)));
+  } else {
+    console.log(t(lang, key, fallback ?? key));
+  }
+}