Ani Omou Yue ni Imouto Ari ~Genteiban~ – Chapter 6

Series Page
Chapter Link (Pages 123-139)
Rating: 5

After Yachiyo finds out the Kaname is dating the MC, she proceeds to seduce and have lesbian sex with her as a “test” to see if she’s suited for him.

Kaname gets very aroused from it and even after Yachiyo wants to stop, Kaname keeps it going off-screen, making her the victor of the “test.”