Houzuki Riko

The most cunning of Daichi's daughters. She agrees to be adopted solely to inherit his wealth with no concern for her new father or sisters. Due to working as a model before being adopted, she has a great figure which she takes great pride in.

She's the only daughter who sees the sexual abuse as an opportunity and she puts up with Daichi's sexually abusive games for profit.

Spoiler

If she's chosen to inherit his fortune, she enjoys flaunting her wealth and she continues to have sex with strangers. When she becomes pregnant, she begins having sex with Daichi hoping that he'll think the child is his and give her more favors-