``Well, sister-in-law, thank you for everything.'' Osamu is deeply grateful to his sister-in-law, Kaori, who not only cleaned up his dilapidated room when his wife went on a trip, but also made dinner for him. - I was grateful. - He didn't even know that Kaori was smiling when she saw Osamu like that. - ``Osamu-san, can I stay the night tonight?'' Osamu readily agrees to Kaori's request, but he has no way of knowing that Kaori's purpose is for Osamu's body.