This summer, Mio's midsummer vacation was cancelled, and she never got to wear her new bikini. Mio, a mother completely depressed, decides to hold a swimsuit fashion show in front of the mirror to cheer herself up. Then her son Kota happens to pass by and offers to give her an oil massage. Kota is excited by the sight of her mother in an erotic bikini that only covers her nipples and private parts, and by the sight of his mother's body, which he is touching for the first time. Mio's sexual desire reaches its peak as she is massaged to her most risqué places...