At a hot-spring inn, a predatory lesbian lusts after a woman traveling with her boyfriend. Pretending their shared bath is an innocent coincidence, she reassures her that it is safe between women and tests her reactions with light touches. She escalates to breast fondling and kissing, then slips a remote vibrator into the woman's pussy underwater and forces her to cum. After overwhelming her with pleasure, she gives her an aphrodisiac and moves on to tribbing and a double-ended dildo.