One of the series' main male protagonists and boyfriend of Kiriko Kiyuna. He fell in love with her at first sight and later confessed to her. Initially he had no knowledge of her past but is later told about it by Kiriko herself. A pure hearted boy, he is loyal and dedicated to Kiriko despite being tempted by other women and always tries to protect her from the Penguin Empire although he is usually saved by her instead. They often engage in romantic and, sometimes, erotic activities in order for Kiriko to release her Hi-ERo particles. As a result, their school's staff has received several complaints due to their Public display of affection.