Mei is the tritagonist to be introduced in Promix Club as Fairy of Biology. She is also a citizen of Cho Chang Empire as well as its Guardian Fairy.
Due to rough chilhood with her divorced parents and cruel uncle and aunt, Mei has become cold-hearted and tended to act arrogantly to people around. She is also sardonic, ironic and reckless. Mei often shows sarcastic and sassy attitude towards those who behave childishly or even know nothing about her aspect of biology, as well as being good at smack-taking.
Mei has a strong desire for being a professional scientist, though every citizens in her homeplanet consider this career to be the men's. She has shown recalcitrance and had an aversion toward people forbading her nurturing the ambition.
When it comes to research something, Mei often gives long, abstract theories than short conclusions, which brings incomprehensibility to everyone and her friends.
Nothing much is known about Mei's pre-series life before attending Alfea Colledge. It is likely that she was born in a countryside of Cho Chang and had a miserable chilhood, when her parents' divorce occured. They sent Mei to her uncle and aunt's family for upbringing, however, the couple is actually an illegal trader, always looked down on Mei and misused her for their wrongdoings.
Mei has a bronze tan complexion