The Ayase couple are in a slump and living a boring, lazy married life. The wife, Rieka, has noticed that her underwear that she hung out to dry has been disappearing recently, and she feels in danger. One evening, as she is about to bring in the laundry, she is attacked by an underwear thief hiding on the balcony. Despite being raped by a man other than her husband, Rieka's pussy gets soaking wet and she feels pleasure. What will become of this married woman who has become the underwear thief's sex slave?!