One night and two days of 1 night and left alone by my wife's sister who suddenly came over

Kazuya makes his wife angry after a marital fight. I was worried about my wife, who had returned to my parents' house with an angry heart, and while I was worried about her, my wife's sister, Naoko, who was going to give me advice. Kazuya, who has been struggling to find a solution and is in a state of trouble, ends up being completely at ease with Naoko, a beautiful and caring person. However, Naoko's true goal was not to stop a fight with her husband, but to relieve her frustration with Kazuya...