Mai Kujaku (孔雀 舞, Kujaku Mai) (literally “Dancing Peacock”) was raised in a wealthy household, but was barely acknowledged by her relatives. While working as a blackjack dealer on a cruise ship, Mai discovered the Duel Monsters card game, and challenged rich men into dueling her. Although a powerful, successful duelist thanks to her Harpie-themed deck, Mai had no true friends, and dueled simply for money and fame. When Mai joined the Duelist Kingdom tournament to seek the three million dollar prize money, she met Yugi Mutou and his friends and steadily forged a true friendship with them after they rescued her Star Chips from the Player Killer of Darkness to help her stay in the tournament. Mai subsequently faced Yugi in the semi-finals, but ultimately chose to surrender to him when she decided she could not win.
Mai returned during the Battle City tournament, where she encountered Shizuka Kawai, Hiroto Honda and Ryuuji Otogi fleeing from the villainous Rare Hunters and helped them to safety. Mai also successfully made it to the quarter-finals of the tournament where she faced Yami Marik, who subjected her to a torturous Shadow Game and almost killed her with the powerful Winged Dragon of Ra. Although Jonouchi and Yugi were able to save her life, she was still the loser of the duel and as punishment had her mind stolen away by Marik, which would lead to her eventual death. Mai was saved when Yugi defeated Marik in the tournament final, and she departed to find her own way in life.
Although Mai does not appear afterwards in the manga, in the anime she takes part in the Paradias arc and joins Dartz as a duelist, because she has been having nightmares about Marik and believes she must defeat Jonouchi to put her past behind her. Although she eventually duels and defeats him, she discovers he was holding back to keep her from danger, and she rebels against Dartz. She is subsequently defeated by Rafael, and restored when Dartz is defeated.