Airi, who married into the Ichimatsu family, started living with her husband and stepson. The stepson was well-behaved in front of his father but did not like Airi acting like a mother after suddenly coming to the house. While the husband was cleaning, he found a video camera and accidentally turned on the recording switch without noticing. Several days later, the husband remembered the video and decided to watch it, only to find footage of Airi being raped by his son. Shocked beyond anger, he continued watching and saw Airi's transformation from reluctant to accepting, and eventually initiating the acts, becoming her stepson's woman day by day.
