diff --git a/day5/.gitattributes b/day5/.gitattributes
new file mode 100644
index 000000000..e5fc7b372
--- /dev/null
+++ b/day5/.gitattributes
@@ -0,0 +1,2 @@
+# 改行コードを LF に統一
+*.py text eol=lf
\ No newline at end of file
diff --git "a/day5/\346\274\224\347\277\2221/models/titanic_model.pkl" "b/day5/\346\274\224\347\277\2221/models/titanic_model.pkl"
index 6fec87e47..18c70435b 100644
Binary files "a/day5/\346\274\224\347\277\2221/models/titanic_model.pkl" and "b/day5/\346\274\224\347\277\2221/models/titanic_model.pkl" differ
diff --git "a/day5/\346\274\224\347\277\2222/black_check.py" "b/day5/\346\274\224\347\277\2222/black_check.py"
index 3158f952d..910a40c3a 100644
--- "a/day5/\346\274\224\347\277\2222/black_check.py"
+++ "b/day5/\346\274\224\347\277\2222/black_check.py"
@@ -1,7 +1,18 @@
+def say_hello(name):
+    print("Hello," + name + "!")  # greet
+
+
+def say_hello(name):
+    print("Hello," + name + "!")  # greet
+
+
+def add(a, b):
+    return a + b
+
+
+def add(a, b):
+    return a + b
+
 
-def say_hello(name):print("Hello,"+name+"!")   # greet
-def say_hello(name):print("Hello,"     +    name   +"!")   # greet
-def add( a,b):return a+b
-def add( a ,     b    ):return a+b
 def add(a, b):
-    return a+b
\ No newline at end of file
+    return a + b
diff --git "a/day5/\346\274\224\347\277\2222/main.py" "b/day5/\346\274\224\347\277\2222/main.py"
index 776b70e75..2b256b6c5 100644
--- "a/day5/\346\274\224\347\277\2222/main.py"
+++ "b/day5/\346\274\224\347\277\2222/main.py"
@@ -11,6 +11,7 @@
 import time
 import great_expectations as gx
 
+
 class DataLoader:
     """データロードを行うクラス"""
 
diff --git "a/day5/\346\274\224\347\277\2222/models/titanic_model.pkl" "b/day5/\346\274\224\347\277\2222/models/titanic_model.pkl"
index 9e1859fdf..f5f5e860b 100644
Binary files "a/day5/\346\274\224\347\277\2222/models/titanic_model.pkl" and "b/day5/\346\274\224\347\277\2222/models/titanic_model.pkl" differ
diff --git "a/day5/\346\274\224\347\277\2223/tests/test_model.py" "b/day5/\346\274\224\347\277\2223/tests/test_model.py"
index e11a19a5c..f4db9ff85 100644
--- "a/day5/\346\274\224\347\277\2223/tests/test_model.py"
+++ "b/day5/\346\274\224\347\277\2223/tests/test_model.py"
@@ -134,6 +134,9 @@ def test_model_inference_time(train_model):
 
     # 推論時間が1秒未満であることを確認
     assert inference_time < 1.0, f"推論時間が長すぎます: {inference_time}秒"
+    assert (
+        inference_time < 2.0
+    ), f"推論時間が長すぎて何か大きな修正が必要です: {inference_time}秒"
 
 
 def test_model_reproducibility(sample_data, preprocessor):
@@ -171,3 +174,18 @@ def test_model_reproducibility(sample_data, preprocessor):
     assert np.array_equal(
         predictions1, predictions2
     ), "モデルの予測結果に再現性がありません"
+
+
+def test_model_is_better_than_random(train_model):
+    """モデルの精度がランダム予測より有意に高いことを検証"""
+    model, X_test, y_test = train_model
+
+    y_pred = model.predict(X_test)
+    model_acc = accuracy_score(y_test, y_pred)
+
+    random_preds = np.random.choice([0, 1], size=len(y_test))
+    random_acc = accuracy_score(y_test, random_preds)
+
+    assert (
+        model_acc >= random_acc + 0.1
+    ), f"モデルの精度がランダムと大差ありません: model={model_acc:.3f}, random={random_acc:.3f}"