The senior of Syo Kurusu and Natsuki Shinomiya. In Debut, it was said that he might be a robot (A.I.) but it was never mentioned in the anime. He's very apt and hardworking, and often act as the mediator whenever both Camus and Ranmaru argue about. He is very strict when it comes to his teaching, his previous students quit after one month of training under him. He goes by, “If they have potential, raise them. If they don’t, drop them.” Ai calls everyone by their first names. His design is based in Aine Kisaragi, a former idol who disappeared years ago. He plays the synthesizer and is 15 years old.