Mai is a snobby uppity girl. She thinks no one need friends and she does not need anyone and all she needs is herself.
She is also one of the top duelists on the world. Mai challenges Joey to a duel and Joey wins. Then she gets Rex Raptor to beat him and He duels him and Joey wins also and not just the duel he also gets Rex's very rare Red Eyes Black Dragon. At first Yugi and his friends are nice to her but she wants nobody. As the Duelist Kingdom Tournament goes on she finds friends are not such a bad thing. She gets into the semis in the Duelist Kingdom Tournament she is beat by Yugi and tells him they will duel again By the Battle City Finals she considers Joey and Yu-gi and the whole gang her friends and they consider her a friend. During the duel with Marik he takes her to duel in the shadow realm where ever time a monster of hers is destroyed she looses someone she knows from her memory but Yugi aids her.
Although Mai at first is heartless she now does belive in friendship thanks to Yugi and friends.