diff --git a/ja_timex/number_normalizer.py b/ja_timex/number_normalizer.py
index 03043f1..c24cc67 100644
--- a/ja_timex/number_normalizer.py
+++ b/ja_timex/number_normalizer.py
@@ -2,13 +2,13 @@
 from dataclasses import dataclass
 from typing import List, Tuple
 
-import mojimoji
-
 zero = {"零": 0}
+zen2han = {"０": 0, "１": 1, "２": 2, "３": 3, "４": 4, "５": 5, "６": 6, "７": 7, "８": 8, "９": 9}
 char2int = {"〇": 0, "一": 1, "二": 2, "三": 3, "四": 4, "五": 5, "六": 6, "七": 7, "八": 8, "九": 9}
 char2power_allow_head = {"十": 1, "百": 2, "千": 3}
 char2power = {"万": 4, "億": 8, "兆": 12, "京": 16, "垓": 20}
 char_int_table = str.maketrans({k: str(v) for k, v in char2int.items()})
+zen_han_table = str.maketrans({k: str(v) for k, v in zen2han.items()})
 
 
 @dataclass
@@ -133,7 +133,7 @@ def _normalize_zen_to_han(self, text: str) -> str:
         Returns:
             str: 半角に正規化した文字列
         """
-        text = mojimoji.zen_to_han(text, kana=False, ascii=False)
+        text = text.translate(zen_han_table)
 
         # 数字の間にはいる,や.の全角文字を半角にする
         re_match = re.search("[0-9][，．][0-9]", text)
diff --git a/poetry.lock b/poetry.lock
index 0c78c7e..8790aae 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1011,28 +1011,6 @@ files = [
     {file = "mkdocs_material_extensions-1.3.tar.gz", hash = "sha256:f0446091503acb110a7cab9349cbc90eeac51b58d1caa92a704a81ca1e24ddbd"},
 ]
 
-[[package]]
-name = "mojimoji"
-version = "0.0.11"
-description = "A fast converter between Japanese hankaku and zenkaku characters"
-optional = false
-python-versions = "*"
-files = [
-    {file = "mojimoji-0.0.11-cp35-cp35m-macosx_10_14_x86_64.whl", hash = "sha256:b86ee36240e77a414f796630cf3c80acef4e9528277769d1851d00b94af1cc98"},
-    {file = "mojimoji-0.0.11-cp35-cp35m-manylinux1_x86_64.whl", hash = "sha256:3d3756f60754ee95847f419f48246a68271d9024c5296d298054229403804002"},
-    {file = "mojimoji-0.0.11-cp35-cp35m-win_amd64.whl", hash = "sha256:e257176fe55332ac5dc69735270840b36738a82f1dda3383758a6f36b5918fb6"},
-    {file = "mojimoji-0.0.11-cp36-cp36m-macosx_10_14_x86_64.whl", hash = "sha256:ece991b6529dddb91ae5035dcf3b62b486af675d4ec94fc3ecf7872b66f3df88"},
-    {file = "mojimoji-0.0.11-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:b7a1fe5726ad7036b096d44e7d014ceac174aec718199e19c6c6d1c2a757f6b9"},
-    {file = "mojimoji-0.0.11-cp36-cp36m-win_amd64.whl", hash = "sha256:ae2fcb9fa35f5890ba888780c9d445074717ef988c3171a058f002cd0f3933f4"},
-    {file = "mojimoji-0.0.11-cp37-cp37m-macosx_10_14_x86_64.whl", hash = "sha256:e551bb3be777643e2e1f7bc40db4d57baedaa6dac6c7875d9a926ffe66b67fb1"},
-    {file = "mojimoji-0.0.11-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:642c5e8642fa53c9556cd4c880e09438786dd955c32c7ce5fa2693e16914cdb6"},
-    {file = "mojimoji-0.0.11-cp37-cp37m-win_amd64.whl", hash = "sha256:029c5d2646c8ab36bef61abe26ed6bc698f7ffb6a744d82fafd86e233d6669a2"},
-    {file = "mojimoji-0.0.11-cp38-cp38-macosx_10_14_x86_64.whl", hash = "sha256:2fb18323ffae39391d77c77b27ed675cbf6e49e10f884ceaf8399be7ca7e0dc5"},
-    {file = "mojimoji-0.0.11-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:ea9c3d0c37ae7a8e494cb9681dae404de4599d4218e5b5d13c009ab1856d6409"},
-    {file = "mojimoji-0.0.11-cp38-cp38-win_amd64.whl", hash = "sha256:304681e2d99db69c552e1e36992cb41b967b46abd1720c1826f9dec678491d56"},
-    {file = "mojimoji-0.0.11.tar.gz", hash = "sha256:adef094e1bfd961e40c1fbd2d4664da1be2426d5b31884e27394226af15d50b5"},
-]
-
 [[package]]
 name = "mypy"
 version = "1.6.0"
diff --git a/pyproject.toml b/pyproject.toml
index fbf7340..4055eb8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,7 +22,6 @@ classifiers = [
 
 [tool.poetry.dependencies]
 python = "^3.8.1"
-mojimoji = "^0.0.11"
 pendulum = "^2.1.2"
 
 [tool.poetry.group.dev.dependencies]