diff --git a/tests/quality/ja.tsv b/tests/quality/ja.tsv
new file mode 100644
index 00000000..8de409d0
--- /dev/null
+++ b/tests/quality/ja.tsv
@@ -0,0 +1,4 @@
+# label	sentence
+init	今日は▁とても▁良い▁天気です。
+init	Google の▁使命は、▁世界中の▁情報を▁整理し、▁世界中の▁人が▁アクセスできて▁使えるように▁する▁ことです。
+#init	これ以上▁利用する▁場合は▁教えてください。
diff --git a/tests/test_quality.py b/tests/test_quality.py
new file mode 100644
index 00000000..4c9e5558
--- /dev/null
+++ b/tests/test_quality.py
@@ -0,0 +1,37 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Quality regression test."""
+
+import os
+import sys
+import unittest
+
+# module hack
+LIB_PATH = os.path.join(os.path.dirname(__file__), '..')
+sys.path.insert(0, os.path.abspath(LIB_PATH))
+
+from budoux import load_default_japanese_parser, utils  # noqa (module hack)
+
+
+class TestQuality(unittest.TestCase):
+
+  def test_ja(self) -> None:
+    parser = load_default_japanese_parser()
+    fp = os.path.join(os.path.dirname(__file__), 'quality', 'ja.tsv')
+    with open(fp, 'r', encoding='utf-8') as f:
+      data = [line.split('\t') for line in f.readlines() if line[0] != '#']
+    expected_sentences = [line[1].strip() for line in data if len(line) > 1]
+    for expected in expected_sentences:
+      result = utils.SEP.join(parser.parse(expected.replace(utils.SEP, '')))
+      self.assertEqual(result, expected)