In DragonBall Mai serves emperor Pilaf together with Shuu. Their goal is world domination. She's the most clever one of their group but screws up her missions anyway. She has long black hair and wears a long coat. She has blue eyes. She mainly uses guns for combat.
Piccolo Daimao arc
Mai and her collegues release the old demon Piccolo Daimao into the world. They first to his bidding believing he will give them a portion of the world to rule. After Piccol Daimao succeeds to wish for youth, he dumps Mai, Pilaf and Shuu because he doesn't need them any more. He only needed them to track down the dragonballs.
This was the last time Mai appeared in the manga. In the anime she made more appearances.
Mai has become an old woman in DragonBall GT. Together with Pilaf and Shuu they find the black star dragonballs, and want them to rule the world once again. This plan fails when Pilaf accidentally wishes Goku to be young again. After this they aren't seen much again.
In DragonBall Evolution (2009) Mai serves Piccolo without the help of Pilaf and Shuu. She has black hair and is dressed completely in red. She also posesses the ability to shapeshift and knows martial arts.
She speaks Japanese and English in the movie. She was portrayed by Eriko Tamura.