Maa is a small kitten with white fur marked by patches of black and brown, and she has striking blue eyes. She first appears as a stray discovered by Alice Carroll, a trainee Undine at the Orange Planet water-guide company, during the events of the first season. Alice adopts her and names her Maa because the only sound the kitten ever makes is a short, sharp "Maa." Because of her small size and blue eyes, which are considered lucky in the world of Aqua, Maa eventually becomes the official president of Orange Planet, a title traditionally held by a blue-eyed cat mascot for each gondola company.

Maa's personality is playful, energetic, and mischievous. She is the smallest of the company cats but makes up for it with curiosity and determination. Her most notable habit is biting the belly of President Aria, the large white cat president of Aria Company, which she does whenever she can and which always annoys President Aria. This recurring comedic interaction highlights her impish nature, but she also displays affection and loyalty toward Alice.

Maa's role in the story is primarily that of a mascot and companion. She appears regularly alongside Alice and often accompanies her on daily routines or joins the other cat presidents in their secret meetings around Neo-Venezia, revealing a hidden, magical side of the city's feline society. Her presence adds warmth and whimsy to the gentle, slice-of-life atmosphere of the series.

Her key relationship is with Alice Carroll. Maa was adopted by Alice, and the two share a close bond. Maa also has a playful relationship with President Aria, whom she loves to pester, and she interacts with other cat presidents like Hime M. Granzchesta.

Over the course of the narrative, Maa develops from a tiny, unruly kitten into a more composed cat, eventually taking on the formal role of Orange Planet's president. This growth mirrors Alice Carroll's own progression from a trainee to a fully fledged Prima Undine, emphasizing the theme of maturation and the importance of small creatures in the larger tapestry of life in Neo-Venezia.

Maa's most distinctive ability is her vocalization: she only says "Maa," which became the basis for her name. She also demonstrates an ability to follow other cats to secret gatherings, hinting at an instinctual understanding of the hidden world of cats in the city. Aside from these, she has no supernatural powers, but her endearing behavior and iconic habit make her a memorable character.