Nephew Takumi visits the Shiraki household and stays overnight during his vacation. That night, while pretending to be considerate of Takumi sleeping in the next room, wife Yuko can't resist her husband's advances and indulges in nocturnal pleasure. Takumi secretly wakes up and witnesses the scene, imprinting it into his memory. From then on, he begins to see Yuko as a woman. Sensing his gaze, Yuko finds herself drawn to Takumi's youthful, vigorous body and starts developing forbidden feelings of her own.