Yoriichi Type Zero is a wind-up Battle Doll constructed by Kotetsu's ancestors. According to Kotetsu's father, it was based off it’s appearance largely resembles Yoriichi Tsugikuni, the person it was modeled after. It has six arms that each hold a katana, due to the fact that two arms weren't enough to come close to replicating Yoriichi's movements. It is also shown to be heavily damaged yet works swift and perfectly with half of its face and one of its arms missing. It can’t speak.