PGD-813 I believe in my sister-in-law. Kawakami Yuu.

A respected older brother and a sister-in-law, Yu, whom she admires like a real sister. I lived happily with two happy people for a short period of time. However, my sister-in-law's behavior is a little strange. A suspicious visitor, pretending to hide something... There is no such thing as an affair with a sister-in-law. In order to protect the peace of this house, I decided to move. I believe in my sister-in-law... Full-fledged sister-in-law cuckold new drama series first!