He works at the Snake Pit Headquarters developing weapons for Tao, and getting intel for her and Alma. Yoki has an enthusiastic and outgoing personality, as seen by the big welcoming embrace he gave them the moment they arrived at the Snake Pit Headquarters. He's also shown to be concerned for them, as he often reminds them to be careful whenever they embark on an action. Yoki is the one who created the bullets for Tao's rifle, which were produced from Alma's blood.