Hibiki Otsuki, a gold-digging private tutor, arrives at the wealthy household of Misako Nakano, her real daughter Mahiru Tsubaki, and her stepdaughter Rei Mizuna. Rei recruits Hibiki into a scheme to kidnap Mahiru and extort a large sum of money. They tie up Misako and, right before her eyes, Hibiki performs cunnilingus on Mahiru while Rei films everything. Rei forces the mother and daughter into performing lesbian acts—tongue kissing, nipple sucking, and fingering—against their will. The coercion intensifies, creating an increasingly disturbing and tense atmosphere.