The Tanihara family is hosting their brother-in-law, Kenzo, for a few days while he goes for a job interview. During that time, Nozomi, the wife, feels a little nervous because her husband is away on a business trip, but before they know it, they have become comfortable with each other and are enjoying an evening drink together. However, Nozomi's body is aching from the alcohol, and she becomes lonely sleeping alone and begins to masturbate. Kenzo, who is unaware of what is going on, visits his sister-in-law's room and is shocked by her lewd appearance, which is completely different from what he would normally expect from his usual sister-in-law. His restrained rationality is completely blown away, and before he knows it, he is lying on top of Nozomi, lying on the bed...