同居している弟の嫁、うみは弟が出張に行く度に俺を誘惑してくる…。さらには出張で弟がいない3日間、自宅に代わる代わる男を連れ込み、俺に見せつけるかのように堂々と浮気をしている。しかし、それを弟には言い出すことは決してできない。なぜなら俺も弟の嫁と関係を持ってしまったから…。　

Whenever my stepbrother's wife, Umi, who lives with him, goes on a business trip, she seduces me. She even takes over for him during the three days he is away on business trips, bringing men into the house and cheating on him as if to show me. But I can never tell my brother about it. Because I had a relationship with my brother's wife too....