Chishiya is a highly intelligent individual. enabling him to survive all types of games. His complete disregard for human life and manipulative nature allow him to use others for his own benefit. He remains calm under any circumstances and analyzes his predicament. Chishiya's past as a doctor. He once treated a young boy named Hayato, who needed a surgery. However, Chishiya learned that Hayato's procedure was postponed and he died. That moment sent Chishiya down the path of becoming cynical. 