is the first-year schoolgirl. She is the classmate of Nana and Momo when they two transfer to Sainan High. Nana becomes her friend after talking to her about Nana's ability to understand animals' language. She reveals to Yami that she is Yami's little sister, and possess similar powers. She desires for Yami to kill Rito and return to her life as an assassin instead of living a normal life on Earth. After she is starting to develop sexual feelings for Rito, and start seeing other people as friends. After Nana found out Mea was a weapon, she told her she was "playing" friends with her. However, Nana made up with her and became friends again.