Mei knew about Sorata Muon, when he was little boy, as she was forced to serve him and decided to be loyal to him eversince then. However, Sorata has no recollection of who she was back then.
Years later, Mei worked a double life with Sorata at the college he works at as a math two teacher, with two other females.
In the first episode, Mei appeared before Mouse, who was late for work, and told him that he needs to be more responsible for showing up late as despite being an art teacher, he is also a professor at the college. Later, as Sorata returned to his apartment, Mei appeared before him, happy with his return, and acts sexually around him, along with Yayoi and Hazuki, although distirbing Sorata. Mei was later seen dressed as a cat as Sorata was watching the news about Onizuka Heitaro, challenging Mouse to steal the Odaiba tower that was builty recently.