Soon after getting married, Nono's husband has been away on a business trip for three months. She lives with her sister and her husband, who are worried about her living alone, and they spend their days peacefully together, but her frustrations are building up and she masturbates almost every day to release them. One day, she finds out that her brother-in-law, Tetsuya, is also having a hard time with sex... What's more, he has an incredibly big dick that she can't control, and Nono can't control the desires of her throbbing body and secretly seduces him. Unable to resist her devilish temptations, they have a relationship, and before she knows it...