Riri Yomari

Riri Yomari or Lilim is one of the characters featured in Succubus Heroines Eroge.

Pre-Transformation
A first year student, one year younger than the main character. She goes to Nishizumi High School. She's the main character's younger sister, but she went with her mother to America after their parents divorced, so they had been separated until now.

When she was a young girl, she was strongly attached to the main character and very clingy. She used to have a meek personality, but now she can be very verbally abusive with him.

For some reason, she's become very cold. Another thing, while living in America, she skipped grades. She was such a genius girl that she was able to attend college early. Her only problem was that she looked a lot younger than her actual age. Also, she has always been great friends with Asuna.

Lilim
Riri, after having become a succubus.

She's never honest about the way she feels, but it was apparent to Asuna that, even now, she still loves her brother. Upon recognizing that fact, Asuna changes her into a succubus.

The transformation into a succubus caused her personality to revert to being completely childish. She's became so clingy that the main character even called her a nutcase. Guided by the instinct of the succubi, she tries to have intercourse with him; however, he turns her away because of incest.

Special pleasure amplification runes have been engraved over half of her body by Asuna. Thus, her whole body has become extremely sensitive to pleasure. So much so that even a simple pat on the head feels like sexual pleasure for her.

Even after becoming a succubus, her genius level intellect is still intact; only now, it is used primarily to develop various sex tools that are to be enjoyed with the main character.

Trivia

 * Although her succubi name is Lilim, there's no relation with the Demon Lord's daughters.