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

I have a brother whom I respect and a sister-in-law, Yuu, whom I adore like a real sister. I ended up living with this happy couple for a short time, and I was enjoying my life. However, my sister-in-law seems to be acting a little strange. There are suspicious visitors, and she seems to be hiding something... There's no way my sister-in-law would cheat on me. In order to protect the peace of this household, I have decided to take action. I believe in my sister-in-law... The first in a new drama series about a serious sister-in-law being cuckolded!