Yuko (Mio Morishita), a married woman working as a personal trainer, regularly invited her friend and her friend's daughter, Aya (Shuri Atomi), to her home to teach them training. For Yuko, who lived a lonely life while her husband was away on a long business trip, the time spent exercising and sweating with the other two women was a joy. However, at that time, she didn't know that Aya, who was one or two decades younger, was targeting Yuko's body. Nor did she know that she would soon drown in both body and soul in Aya's skillful lesbian techniques.