Heidayuu Sasayama  

, 笹山 兵太夫

The individual born into a family of martial arts practitioners possesses decisiveness, stubbornness, mischievous tendencies, and cynicism. He is known for his proficiency in traps, machinery, and mechanical engineering. His living quarters with Sanjirou are filled with various devices and traps they have created together. Additionally, the Headmaster has granted him permission to construct an additional room beneath their shared space, which he uses as a personal workshop for his inventions.