Normally a slender, slim man with black hair who acts strict but possesses a pure heart. Due to his constitution, he turns into a massive bodybuilder whenever he feels embarrassed or his heart flutters. He always wears custom-made clothes made of special fibers that stretch and shrink easily. He often says things like, "Stop making my heart race!" If he turns muscular, he will return to normal if he is calmed down or if something depressing is said to him. He has a serious personality.