When my husband was away on a business trip, my beloved brother, who lived at home, suddenly moved to Tokyo. Natsuki, her older brother, offers to use her spare room, and she accepts the offer. When I asked my brother why he came to Tokyo, he told me that he broke up with his girlfriend because of sex, and that he wanted to hone his sex skills at an adult entertainment business. However, the prostitute he was looking for had quit, so the older brother, at a loss, took advantage of his younger sister's personality and offered her a practice table. Unable to refuse his beloved older brother's request, he graciously accepted.