I work at a publishing company and live alone in a large house. My wife has a lot of business trips and less time together, and I was asked many times every time I returned home, and I was exhausted. My sister-in-law Erika often came to visit me whether she knew me or not. That day, too, the conversation changed from small talk to night life, and Eri, who had a mischievous expression, touched my crotch. Erika whispered to me that I lost my reason and wanted my body, and that if I could abstain for 30 days, I could fall in love with her.