A first year in Hayaka Hirayama's class, and a strong protector of her safety. He has feelings for Hayaka, but she doesn't understand them/doesn't seem to be aware of them herself. Katou often acts a "big brother type"/guardian to Hayaka, straightening her school uniform buttons etc, and protecting her from danger. He excels at sports, but has never really been interested in club activities due to taking care of his younger siblings, as well as cooking and housework for his family -- which in total has 12 members. He wishes to study in an industrial school to get a national qualification license for something like Dangerous Substances, or to become a fireman.