A 56-year-old married teacher has spent his life following the rules, only to realize that a strictly moral existence has left him empty. Then Rino, portrayed as his adult student, captivates him with her radiant smile, unwavering gaze, uniform, and temptation. He begins an affair with a woman more than twenty years younger, repeatedly seeking forbidden sex despite knowing it makes him an unfaithful husband and a failed teacher. The guilt itself becomes intoxicating, and although he grows increasingly ashamed of his behavior, she never turns away. Through their immoral relationship, he feels he may have found the greatest happiness of his life.