48-year-old Natsuko is a married woman celebrating 26 years of marriage. Having lived earnestly up to this point, she begins questioning her life and secretly harbors a desire to be seduced by another man behind her husband's back. At a reunion for her alma mater ■■ High School—held for the first time in 25 years—she becomes intrigued by stories of infidelity, sparking a new sense of excitement. Shocked by a classmate's revelation about an affair with her son's private tutor, Natsuko confronts her own loneliness. While reminiscing about fleeting memories from the past, she feels an overwhelming urge to seek new experiences and decides to apply. Twenty years after last baring her body before a man, Natsuko spreads her legs on command and accepts another man's cock—one that isn't her husband's—into her. She experiences firsthand the intense mix of pleasure and tension in that moment.