Wife Yuki (Morishita Mio), making use of her skills as a personal trainer, invited her friend's daughter Aya (Shuri Atomi) to her home to train together during her husband's long business trip, hoping to make her lonely days a little more enjoyable. For her, the time spent sweating together with two other women was a precious escape from solitude. But she didn't realize what was happening that day—Aya, much younger and secretly attracted to her, was setting her sights on Yuki's body. Gradually, Yuki found herself falling under the spell of Aya's lesbian techniques.