diff --git a/requirements-dev.txt b/requirements-dev.txt
index 2c877c547..9b274bec2 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -28,6 +28,7 @@ jeepney==0.8.0 ; python_version >= "3.11" and python_version < "3.12" and sys_pl
 jinja2==3.1.2 ; python_version >= "3.11" and python_version < "3.12"
 jsonschema==4.17.3 ; python_version >= "3.11" and python_version < "3.12"
 keyring==24.2.0 ; python_version >= "3.11" and python_version < "3.12"
+ko2kana==1.8 ; python_version >= "3.11" and python_version < "3.12"
 macholib==1.16.2 ; python_version >= "3.11" and python_version < "3.12" and sys_platform == "darwin"
 markupsafe==2.1.3 ; python_version >= "3.11" and python_version < "3.12"
 more-itertools==10.1.0 ; python_version >= "3.11" and python_version < "3.12"
diff --git a/requirements-test.txt b/requirements-test.txt
index ea3290c26..e3802c18d 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -39,6 +39,7 @@ jeepney==0.8.0 ; python_version >= "3.11" and python_version < "3.12" and sys_pl
 jinja2==3.1.2 ; python_version >= "3.11" and python_version < "3.12"
 jsonschema==4.17.3 ; python_version >= "3.11" and python_version < "3.12"
 keyring==24.2.0 ; python_version >= "3.11" and python_version < "3.12"
+ko2kana==1.8 ; python_version >= "3.11" and python_version < "3.12"
 markupsafe==2.1.3 ; python_version >= "3.11" and python_version < "3.12"
 mccabe==0.7.0 ; python_version >= "3.11" and python_version < "3.12"
 more-itertools==10.1.0 ; python_version >= "3.11" and python_version < "3.12"
diff --git a/requirements.txt b/requirements.txt
index aa124e9c6..ed40a3faa 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,6 +8,7 @@ fastapi==0.103.2 ; python_version >= "3.11" and python_version < "3.12"
 h11==0.14.0 ; python_version >= "3.11" and python_version < "3.12"
 idna==3.4 ; python_version >= "3.11" and python_version < "3.12"
 jinja2==3.1.2 ; python_version >= "3.11" and python_version < "3.12"
+ko2kana==1.8 ; python_version >= "3.11" and python_version < "3.12"
 markupsafe==2.1.3 ; python_version >= "3.11" and python_version < "3.12"
 numpy==1.26.2 ; python_version >= "3.11" and python_version < "3.12"
 platformdirs==3.10.0 ; python_version >= "3.11" and python_version < "3.12"
diff --git a/run.py b/run.py
index 34671965a..ec2917b8c 100644
--- a/run.py
+++ b/run.py
@@ -22,8 +22,8 @@
 from fastapi.openapi.utils import get_openapi
 from fastapi.responses import JSONResponse
 from fastapi.templating import Jinja2Templates
+from ko2kana import toKana
 from pydantic import ValidationError, parse_obj_as
-from starlette.background import BackgroundTask
 from starlette.middleware.errors import ServerErrorMiddleware
 from starlette.responses import FileResponse
 
@@ -137,6 +137,7 @@ def generate_app(
     latest_core_version: str,
     setting_loader: SettingHandler,
     preset_manager: PresetManager,
+    experimental_katakana_transcription: bool,
     cancellable_engine: CancellableEngine | None = None,
     root_dir: Optional[Path] = None,
     cors_policy_mode: CorsPolicyMode = CorsPolicyMode.localapps,
@@ -280,6 +281,8 @@ def audio_query(
         """
         engine = get_engine(core_version)
         core = get_core(core_version)
+        if experimental_katakana_transcription:
+            text = toKana(text).replace(" ", "")
         accent_phrases = engine.create_accent_phrases(text, style_id)
         return AudioQuery(
             accent_phrases=accent_phrases,
@@ -321,6 +324,8 @@ def audio_query_from_preset(
         else:
             raise HTTPException(status_code=422, detail="該当するプリセットIDが見つかりません")
 
+        if experimental_katakana_transcription:
+            text = toKana(text).replace(" ", "")
         accent_phrases = engine.create_accent_phrases(text, selected_preset.style_id)
         return AudioQuery(
             accent_phrases=accent_phrases,
@@ -371,6 +376,8 @@ def accent_phrases(
                     status_code=400, detail=ParseKanaBadRequest(err).dict()
                 )
         else:
+            if experimental_katakana_transcription:
+                text = toKana(text).replace(" ", "")
             return engine.create_accent_phrases(text, style_id)
 
     @app.post(
@@ -1495,6 +1502,12 @@ def main() -> None:
         ),
     )
 
+    parser.add_argument(
+        "--experimental_katakana_transcription",
+        action="store_true",
+        help="韓国語と英語の発音をカタカナに置き換えます。数字は変換しません。",
+    )
+
     parser.add_argument(
         "--disable_mutable_api",
         action="store_true",
@@ -1595,6 +1608,7 @@ def main() -> None:
             latest_core_version,
             setting_loader,
             preset_manager=preset_manager,
+            experimental_katakana_transcription=args.experimental_katakana_transcription,
             cancellable_engine=cancellable_engine,
             root_dir=root_dir,
             cors_policy_mode=cors_policy_mode,