Also known as: 二階堂浩平
A Golden Kamuy character. He and Nikaidou Youhei are identical twin Brothers. Over the course of the story, Kouhei has lost both of his ears, one arm, and one leg; he uses prosthetics for his missing limbs. Following Youhei's death, he kept one of his severed ears tied to a string around his neck, talking to it as though it were his brother's. He later had it attached to a headpiece by Edogai Yasaku.