One day on a holiday, Jun comes to her house to play, and is captivated by her mother Sayuri's beauty and sexiness, which doesn't seem to reflect her age, when he sees her for the first time. Perhaps sensing Jun's feelings, Sayuri takes advantage of her daughter's absence to try and seduce Jun by flirting with her... Jun is seduced by Sayuri's charms and completely loses his sense of reason, eventually forgetting that she is his girlfriend's parent and having a relationship with her. Since then, he begins to enjoy secret rendezvous with his mother, Sayuri, under the guise of a date at home with her...