Mary Ann (メリー・アン?) is a minor character in Star☆Twinkle Pretty Cure and its movie who is a police detective instructed to arrest Blue Cat.
Mary Ann is a brown dog like alien with cyan colored eyes and lilac colored hair tied into a high ponytail. On her head, she wears large grey goggles and a green and yellow clip to keep her hair parted. She is seen wearing a red vest and skirt with dark blue trims. Keeping her vest together is a gold buckle. She wears a white dress shirt underneath with a green tie. She wears brown gloves on her hands as well as white, brown and dark blue shoes with a gold buckle.
Mary Ann is a diligent girl who will do her hardest to get the job done. Despite that, she is rather absent-minded, often doing exactly the things she is against. At times, she can be clingy when it comes to desperately wanting to accomplish her missions, such as arresting Yuni, and such persistence can annoy others.
In episode 36, Mary Ann first appears being promoted to her police detective role. Her first assignment was to infiltrate a mafia's base, but while there she comes across Blue Cat, who she has always wanted to arrest. She successfully sees through Blue Cat's disguises but ends up being seen as a bad guy by Don Octo since she had snuck onto Don Octo's ship as well. She is rescued by Blue Cat, only for them to be captured by Don Octo anyway. While tied to a pole, Mary Ann tells Yuni to stop stealing things only to be questioned by Yuni herself. After being rescued by Hikaru and the others, they are confronted by Don Octo as well as Tenjo, who turns Don Octo into a Nottorei. She thus witnesses the five girls becoming Cures, and is surprised by Yuni being one as well. Despite that, she teams up with them as a way to thank Yuni for trying to rescue her. After the battle, she tries to get Yuni to pay for her crimes by doing ten years of volunteer work for her, however Yuni outwits her and escapes. She gives chase but ends up speeding past the girls and crash landing in the moon.
In the movie, Mary Ann rushes in to help the Cures to defeat Tenjo. However, she quickly switches her aim to arrest Yuni, thus she has a space chase with the rocket with her cab, and accidentally drops her Miracle Light without noticing. After the space hunters have been arrested, she explains to the Cures that she has to take UMA along because UMA is a Star Drop that is being sought after, and if UMA is undisturbed, they will become a planet when it is not being negatively influenced. After UMA becomes a planet, Mary Ann successfully arrests all of the hunters.
- Yuni - Her sole purpose of being a police detective was to arrest Blue Cat. However, when she meets Yuni, Mary Ann realises she's very different from what she had heard about. This doesn't stop her from pursuing Yuni though.