Ayano's boyfriend whom she met at the "Meet the Boys" festival.
Eriko and pals, as well as Ayano's mother and sister, are usually trying to get Ayano to lose her virginity to him, mostly without the couple's consent.
Often the butt of many pranks by Eriko and her group, Himeji used to have a crush on him before she discovered how vain he is. A bitter older woman who always seems to have a scowl on her face.
Chapter 69 is told from his point of view, showing him to be far less vain and perverted than the girls believe him to be. Constantly seen wearing an out-dated 1970s style leisure suit (which is later burned at a school bonfire), decidedly elected as "The teacher who most likely needs Viagra". She dyes her hair black to cover her grays (even though hair dyeing is against the Saki Girl's rules).
She tends to be the main victim of the perverted actions (accidental or not) of Odagiri, though she occasionally uses this to blackmail him. She tends to lack in prudence, and ever willing to have fun. She often is victim to getting hit by the others for PDA's.