She is the assistant of Phoenix Wright, who she met in a case related to her sister's death. Wright was able to prove her innocence in that case. Afterwards she was always there to help Phoenix in trials he was in.
She is a very cheerful and often childish person. Maya is obsessed with burgers (ramen in the Japanese version), and action-shows for children, like 'The Steel Samurai', and often annoys Phoenix, but he cares a lot for her.
Like the rest of her family, she is a spirit medium. She uses her powers to channel the spirits of deceased people multiple times throughout the Ace Attorney series games.
She has an older sister named Mia Fey, who is the late mentor of Phoenix, and a little cousin named Pearl Fey. Maya and Pearl have a strong relationship and they are like sisters in the games. Pearl often says that "Mystic Maya is Mr. Nick's (Phoenix) special someone", because she believes that Maya and Phoenix are in love.
After the professor and his assistant, Luke, have been absorbed by the book, we begin with Phoenix wright, and of course his assistant and subject of this page, Maya Fey, who had arrived in England for Mr. Wright's course. Apparently, they did not know about their case, but soon found out that they were defending a school girl named Espella, who resembles the real Espella, but she had a glazed look, not seeming to remember anything that had happened previously with the Professor and Luke. Although before the trial had started, Espella had said that she wasn't a witch.
During the trial, both Maya and Phoenix had managed to obtain a non-guilty verdict for Espella, proving that she didn't attack the victim, who turned out to be a master thief sending the stolen goods out of London through the cargo of the ship she worked at as a chef. Not long after the non-guilty verdict, both Maya and Phoenix had been whisked away in the same book in the exact same manner as the Professor and Luke.
When the player found both Maya and Phoenix, both of them believed they had been living in Labrynthia, the city in the book, and had been bakers most of their lives. After the Professor and Luke return from the Archive, knights had approached, asking for Phoenix to defend Espella, who had been convicted of burning two hoodlums that had tried to rob her, killing them. Before the trial was about to start, both Maya and Phoenix witnessed a guilty verdict on a previous case, thus dropping the witch, who had been in a cage, into a pit of flames, thus ending the witch's life.
With help from Professor Layton and Luke, the defending duo managed to reveal the real witch as the flower girl, trying to convict Espella as the Great Witch, Bezella, the source of all witches, and to stop all of the witch trials as a result. Of course, into the pit went the real witch as she pleaded for them to convict Espella.