Kanzen Osu Dorei ~Kyuuketsuki Shimai to Osananajimi no Sei Gangu ni Sareta Boku~

Faint-hearted, small and otaku protagonist suffers the harassment with abusive words from his childhood friend.
He wanted to change that, and he was intrigued by an ad on the Internet that said: "Do you want to change yourself? A simple test will tell your true self." Click by accident, he filled the forms.

At that time, nothing happened. He went to sleep and woke up to find a pretty vampire girl stepping upon his groin!?

This was the start of a week of sexual assault nightmare for him...

[From DLsite English]