Five years after her husband passed away, Mizuki plans to remarry soon after getting on good terms with a man who had a relationship with a neighbor.Since her son and her partner's son Manabu are in the same class, she should be able to enjoy building her new home.However, her gear begins to go crazy because her study has peeked at Mizuki's masturbation.Manabu, who can't stand her anymore, pushes Mizuki down and even treats her like a dog and begins to train her...