Kinzoku Slime wo Taoshi Makutta Ore ga "Kurokou no Ou" to Yobareru MadeSlime Slayer: From Zero To Black Steel King; 金属スライムを倒しまくった俺が【黒鋼の王】と呼ばれるまで; Kinzoku Slime wo Taoshi Makutta Ore ga "Kurokou no Ou" to Yobareru Made; Until I Came to Be Called “Black Steel King” for Slaying a Bunch of Metal Slimes

One day, a large hole opened up in the yard of a house. There was a mysterious slime with a metallic body that was trembling and shaking.For some reason, Yuma Mitaka, a dull high school student, spends his days exterminating the "metallic slime" that springs up in the hole every morning. As he repeats this daily routine, Yuma's body undergoes an astonishing evolution!This is an unprecedented Musou fantasy that begins with an ordinary day!