diff --git a/update_db.py b/update_db.py
index f80c31d..4e4e420 100644
--- a/update_db.py
+++ b/update_db.py
@@ -16,6 +16,7 @@ import unicodedata
 from datetime import datetime, timedelta
 from typing import Any, TypedDict, cast
 
+import jaconv
 import requests
 from eloquent import DatabaseManager, Model
 
@@ -256,7 +257,7 @@ class CommentResult (TypedDict):
 def normalise (
         s:  str,
 ) -> str:
-    return unicodedata.normalize ('NFKC', s).lower ()
+    return jaconv.hira2kata (unicodedata.normalize ('NFKC', s)).lower ()
 
 
 if __name__ == '__main__':