Mushitaro is a somewhat stuck-up man who takes pride in his ability. He is not a particularly loyal member of the Rats, saying that it only serves to fulfill his own goals. For example, when he met Fyodor Dostoevsky, he demanded a base of operations all for himself, including a bookshelf with occult books and fine china tableware. He is a formidable opponent against Ranpo Edogawa due to his ability. However, he easily breaks when his old friend Yokomizo is brought to mind from his death.