During my wife's pregnancy, even masturbation was forbidden, and I had sex with my sister-in-law, Yu, who had come to Tokyo many times ... Shinoda Yu

Yu, the sister-in-law, is taking care of her pregnant sister Mai while her husband is away on a business trip. However, Kenji, the husband, is unable to control his desires and starts an affair with Yu, engaging in intense and passionate sex, including blowjob and creampie. As they continue their secret trysts, they struggle to keep their actions hidden from Mai, who is unaware of the betrayal happening under her own roof.