Ai Subeki Sadist
To be honest, I ship the MC more with his older brother, even though he is an ass, I like him. Their backstory is much more interesting. I'm really into incest, but they are not blood-related anyway.
Yonin no Nibiiro
Damn, this is so dark, tragic, and full of rape and incest. But I still like this. I love Ai, he is so handsome. What really surprised me here is the change of sex position, such as Betty/Roku, a slutty bottom became a top to Yu, which is, I don't mind, their first sex in a few last chapters is hot. I hope Yu and Ai have sex too, the amount of sexual tension between them is high. But what I don't really like is when Makoto gets raped and becomes a slave to some noob yakuza. I always feel uncomfortable reading it. I don't really mind if it's between Ai and Makoto. Their sex is hot. Overall, this plot is really interesting.
Seitokaicho wa Geboku ni Naritai