Five years into marriage, Haruka is bored with her repetitive life. Her jealous husband refuses to let her train alone with a male personal trainer, so she convinces him to approve a public pool frequented mostly by older patrons. That night she tries on her old competition swimsuit, gets aroused by how tightly it digs in, and masturbates. The next day she wears an even smaller suit to the pool, where obscene stares and a persistent middle-aged neighbor draw the slender, big-ass wife into humiliating swimsuit sex.