Hato is a first year male student and the last to join during Ogiue's first membership drive. Although his sexuality is unknown, Hato shares the fujoshi love of yaoi and boy's love manga and doujinshi, making him a "fudanshi." Because of this, Hato decided to adopt a female persona, complete with a near perfect female voice, and only attends Genshiken meetings as a girl, though he attends classes as a guy. Even after the members of Genshiken learn his secret, Hato continues to cross-dress for the meetings, leading Genshiken to draft former member Madarame into letting Hato change at his apartment.
As a girl, Hato looks and sounds the part so well, guys on campus begin trying to learn more about this "mysterious beauty" who only shows up after classes are over for the day. Indeed, Yajima had a hard time believing someone that looked so beautiful as a girl could really be a guy, but she saw the evidence first hand when Yoshitake and Hato came to her apartment and the trio got drunk. Hato doesn't believe that people see him as very beautiful when he dresses as a girl. Like Sue, Yoshitake, and Yajima, Hato is also one of Ogiue's paid assistants for her professional manga. Being gifted at drawing, Hato helps with the background imagery.