Yubikiri

Lacy is a normal girl living an average life in Tokyo. Or is she? She claims that she didn't kill her parents. She hasn't pinky sweared in years, and she might change her mind. She meets a young girl named Veronica who turns out to be her cousin and claims that Lacy killed her parents.

Funny how that seems.

Lacy may be out numbered, and wait till the people in Tokyo find out.