Mary McGuire is an anime only character who appears in episode 6. She is a professional pianist from San Francisco (Mexico or some country in Latin America in the 4Kids dub), that Ryou and Keiichiro hired to play at a party that the Mew Mews are invited to.
Mary is a tall, light-skinned woman with long, light brown hair that she keeps back with a headband. She wears formal, business clothing when visiting the café but is seen wearing a fancy white dress during her performance at the party.
Tokyo Mew Mew
Ichigo, frustrated due to having to work at the café on a Sunday, hears a woman talking and looks over. Mary is trying to talk to Ichigo and Retasu about playing piano at a party. The only problem: She can only speak English! Retasu, not knowing what to do, runs into the café for help, leaving Ichigo to panic over what to do. She tries to speak to Mary but her English only comes out as nonsense. Aoyama comes over and, luckily, he knows a little bit of English and explains to Ichigo that Mary came to talk to Ryou about a party that she was hired to perform at. Keiichiro then comes over and introduces Ryou to her and it turns out that Ryou and Keiichiro can speak English as well.
When Ichigo, Minto and Retasu come into the café, they hear Mary playing and are amazed. Keiichiro explains to the girls about the party and they're invited. Mary then goes to Ichigo saying that she likes playing the piano for cute girls like her and leaves. Keiichiro tells them that the reason Ryou chose her to play was because he sensed a pureness in her soul when she played.
After Mary plays the piano at the party, she goes out only to be attacked by Quiche. Quiche decides to make more powerful Chimera Animas by combining them with human spirits and Mary is his first target. Doing it causes Mary to turn into a Chimera and she proves to be too tough for the Mew Mews. Ryou tells Keiichiro to play a recording of Mary's piano music and uses it to remind Mary of the pureness of her soul. This causes the Chimera to stop attacking so that Ichigo delivers the finishing move.
Mary's spirit is returned and she thanks Ichigo for saving her.
Mew Mew Power
In order to keep the language barrier, the English dub makes Mary speak Spanish and changed her name to Maria Rivera to change her heritage. It is also hinted that she also knows some English due to her thanking Zoey in English at the very end of the episode.
- All Tokyo Mew Mew dubs keep her original name, along with her speaking English.
- All of the Mew Mew Power dubs keep the name change, Maria Rivera.
- In the Spanish, Serbian and Hebrew dubs, they change her native language back to English.
- The only Tokyo Mew Mew dubs to redo Mary McGuire's voice were the Italian, Mandarin and Korean dubs. The other versions just keep the original Japanese audio when the characters are speaking English.
- The only Mew Mew Power dubs to redo Maria Rivera's voice, when speaking Spanish, were the French and Greek dubs. They did it to give her a Castilian Spanish accent, which is more common to hear in Europe than Latino Spanish. The other dubs kept the English dubbed audio when Maria spoke and some even kept the English audio when other characters spoke Spanish.
- In the manga version (which is sort of a combination of episodes 6, 19 and 41), it is Keiichiro who plays the piano at the party and all 5 Mew Mews were present.