I Killed So Many Slimes I Became Known As The Black Steel KingSlime Slayer: From Zero To Black Steel King; Kinzoku Slime wo Taoshi Makutta Ore ga "Kurokou no Ou" to Yobareru Made; 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

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!