diff --git a/.gitignore b/.gitignore
index 680364b..88d8214 100644
--- a/.gitignore
+++ b/.gitignore
@@ -163,3 +163,6 @@ cython_debug/
 #.idea/
 
 data/
+_*
+.tool-versions
+.vscode
\ No newline at end of file
diff --git a/poetry.lock b/poetry.lock
index da20c33..e7fab80 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -824,6 +824,17 @@ spacy = ">=3.2.0,<3.5.0"
 sudachidict-core = ">=20210802"
 sudachipy = ">=0.6.2,<0.7.0"
 
+[[package]]
+name = "jaconv"
+version = "0.3.4"
+description = "Pure-Python Japanese character interconverter for Hiragana, Katakana, Hankaku, Zenkaku and more"
+category = "main"
+optional = false
+python-versions = "*"
+files = [
+    {file = "jaconv-0.3.4.tar.gz", hash = "sha256:9e7c55f3f0b0e2dbad62f6c9fa0c30fc6fffdbb78297955509d90856b3a31d6d"},
+]
+
 [[package]]
 name = "jedi"
 version = "0.18.2"
@@ -2873,4 +2884,4 @@ files = [
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.10"
-content-hash = "d83e7e36ddfebb7e119c42b4a3d8e5e6822fb1d84dedb9d8f557857b64960eee"
+content-hash = "0ec56ce3c3399574e5029efccec242bbc1d3ea8f0eb9ac122d64ce9249c00a3c"
diff --git a/pyproject.toml b/pyproject.toml
index 18a5e52..c85d230 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,12 +7,13 @@ license = "MIT"
 readme = "README.md"
 
 [tool.poetry.dependencies]
-python = "^3.10"
+python = "^3.9"
 ginza = "^5.1.2"
 ja-ginza = "^5.1.2"
 pandas = "^1.5.3"
 numpy = "^1.24.2"
 fire = "^0.5.0"
+jaconv = "^0.3.4"
 
 [tool.poetry.group.dev.dependencies]
 pytest = "^7.2.2"