Yuka who lived alone for a while in the long term business trip of wife and incense. His mother-in-law, Sayako, was asked to take care of him. Unlike the wife of sanzaimi, Yukichi, a housewife who has been friendly to her, has a kind of personality and a mature body. He was unable to hold down the strong stick of his son-in-law, and Sayako made him ejaculate to be flushed. However, the body is crushed reason, and it is easy to surpass the forbidden line.