I'm a part-time worker and currently live with my older brother and his wife. My brother is a salesman working for a trading company. He's always busy meeting his quota, so he gets up early in the morning and comes home late. Sometimes he works overtime and doesn't come home at all. That's why I spend a lot of time alone with my brother's wife, Kyoko. Kyoko is beautiful and kind, and treats me like a friend. That is, until I saw her like that...