Miho Ashina is a married woman living with her husband and his son from a previous marriage. Neglected by her husband, she finds solace in masturbation and an affair with an insurance salesman. One day, she discovers her stepson's hidden collection of photos and videos—lewd secret recordings of her. Shocked and vulnerable, Miho is blackmailed into submission. Burning with shame, she is forced to obey her stepson's demands, becoming his unwilling sex slave as he exploits her deepest humiliations.