Headcannon where Japan learned how to make paper cranes from a little girl who suffered from a sickness that cannot be treated before when he used fresh bodies to experiment with.
He had hated it, seeing them scream for mercy but he had no choice. So one time he left, He had met the girl who had his wish to make a thousand paper cranes. When he realized that she was one of the victims, He couldn't control himself for he had already loved the girl like his daughter. When the girl died, He was the one who made her wish come true.
