The best sex is sex while going back to my wife's wife

Naomi who lives with her mother and sends married life in her parents' home. The days of passing down with the husband who did not look at home at work recently continued. Keiko, her older sister, returned to her home with her husband Toru Toru. After dinner, it was Naomi, who fell in love with Toru, and spared grief for her husband, but Toru was also worried about the cold relationship. The two people who are close to each other by the common worries, and the unrelated relation, can not suppress desire and drowned in W adultery.