Sayuri Hayama plays a beautiful woman, who, despite having a grown son, remains lovely and attractive like a girl in her twenties. To achieve such a perfect body, Sayuri has worked out very hard. Partly to look beautiful and partly to relieve some of her desires, as her husband is often on business trips and comes home only a few times a year. One day, Kuroi, her son's best friend, came over to visit. From the first meeting, the boy was captivated by Sayuri's amazing body. Sayuri felt the same, as Kuroi is a gym-goer with a very muscular and toned physique, so she was sure that Kuroi's endowment would be impressive. Sayuri also did not hesitate to make teasing remarks full of innuendo towards Kuroi. After that meeting, Kuroi would come by his best friend's house every day just to admire Sayuri, and eventually, what was meant to happen, happened.