Obsessed with seeing his beloved girlfriend Minami taken by another man, her boyfriend hires a professional partner-stealing service. He worries it may fail because she is normally intensely dominant, but sex with a stranger awakens a deeply submissive, masochistic side. She becomes hooked on rough fucking and squirts repeatedly—something she never did with her boyfriend. Humiliated yet wildly aroused, he realizes he is just as hopelessly masochistic.