Shin Yasuda

A small ponytail gathers Yasuda's shoulder-length, maroon-toned hair, while two loose strands are left to fall forward and frame his jaw. His eyes share that same deep red coloring. He presents himself as the picture of a young, approachable instructor, an image that keeps him popular among the students who do not know him well.

Yasuda makes no secret of his fixation on high-school and teenage girls, though he stops short of ever laying a hand on any of them. Instead he lavishes exaggerated warmth on the female students and turns frosty toward the boys. He routinely pesters any male with a girlfriend, chiefly Izumi Miyamura and Kakeru Sengoku, to break things off so the girl might become available to him. Left in a room full of only male pupils, he grumbles aloud about the injustice, and he cannot be bothered to memorize their names, dismissing the effort as pointless.

The girls who are oblivious to all this see only a good-looking, easygoing teacher and happily drop by the counseling room, which he never discourages. The students who have him figured out treat him as fair game, needling him or brushing him off entirely. The central cast in particular strips him of any respect, addressing him simply as "Yasuda" with no title attached and speaking to him bluntly, often telling him to be quiet or go away. When Terajima once chewed him out over his conduct, he briefly reinvented himself as a champion of good manners, even lecturing Hori for raising her voice, but the act lasted a single school day before he reverted.

Envious of the genuine admiration his colleagues command, Yasuda keeps trying and failing to win his students over. His authority is thin enough that the group repeatedly slips things past him: they smuggled the non-student Kouichi Shindo onto campus by convincing him Shindo was simply a face he had forgotten, and later browbeat him into overlooking a whole cake carried in from the Miyamura family bakery. Ishikawa flatly labels him a poor teacher, a judgment reinforced when Yasuda stashes that contraband cake in the staff refrigerator to keep it from melting.

Reiko Terajima, a fellow teacher, is openly antagonistic toward him and appoints herself protector of the students against his advances; she brands him a lolicon and stays hostile even when no girls are present, though he occasionally pushes back and deflates her when she gets carried away. He also shares a past with Kazuya Nakamine, since the two attended Katagiri together, a fact Yasuda has entirely forgotten. Their dynamic as colleagues mirrors their school days, with Yasuda perpetually annoyed and Nakamine treating everything as a joke.