Mia is a cute little mouse who is a bit of a tomboy, she is full of energy, audacity and is somewhat stubborn. Mia loves adventure and discovery, but does not take risk-taking as seriously as she should. She does not always think about the consequences of her actions and can get herself and others into some pretty awkward situations.
Mia is bright, extroverted and a bit of a clown, she craves being the center of attention and is a natural born leader. Her curiosity, which is both a blessing and a curse, is always leading her and her friends to new adventures.
One of Mia’s favorite expressions is "Jeronimouse!". Mia lives in the attic of an old Victorian cottage on Carrington Lane and is just starting to explore the world around her.
Marty is very smart but sometimes he gets overwhelmed by his emotions, finding them temporarily debilitating. He doesn't always believe in himself and shies away from trying out new things.That is why Mia is always pushing him, but once he gets going, there's no stopping him!
Marty is a bit confused by his father not having a very intellectual approach to life. Nonetheless, he loves his father very much. Because his mother died when he was very young, Marty and his father often seem to need a woman’s influence in their lives and, of course, Mia is always happy to oblige.
Despite being confined to a wheelchair Grandma Mimi is a self-reliant, old-fashioned, cookie baking, detective novel reading, kindly Grandma who, quite unsuspectingly, has an intuition like a radar. She’s either very timely or half psychic because she often gives advice at the beginning of the day that comes in very handy by the time late afternoon comes around.
Grandma Mimi is resourceful and an expert at recycling, turning seemingly useless items into whatever she might need. Even though Marty is always keen to improve the mobility of Grandma Mimi’s wheelchair – and she lets him even though there are sometimes startling consequences – she is nevertheless reliant upon Mia, Marty, and the others to seek out bread crusts, cheese bits and any other potential mouse food they might need.
Romaine Rat is generally the bad guy, although it is not really what he wants to be, but his greed almost always gets the best of him.
Romaine is an entrepreneur whose main client is the General Store. Romaine spends his time roaming the countryside finding products that he can sell to the storekeeper. Like any good businessman, he always has his eyes wide open in order to spot any opportunities. Romaine has a deep passion for "Sparklies" which are diamond-like pieces of cut glass and plastic that are used as the currency in Mia’s world.
Mister Maurice is Marty’s father, he is a very jolly mouse and owns the local General Store. Marty’s mother died when he was only a year old and Mister Maurice has raised his son alone.
Mister Maurice has always been a little puzzled about his intellectual son, Marty, who never liked sports and always prefers a good book to an adventure. Mister Maurice finds that he can relate better to Mia and often relies on her to relay his feelings and concerns for him. Fortunately, Mia is around to motivate Marty, which pleases Mister Maurice and makes him want to futher encourage their friendship.
Mister Maurice’s business relationship with Romaine Rat has always been a little bizarre, however Romaine always manages to get whatever stock that the storekeeper may need.
Miguel is a recent arrival to Mia’s world. He has come all the way from Mexico and misses his family very much.
Miguel has a gift for mechanics and has built an elevator for all the mice to use. For this everyone is very grateful as many of the local mice have run into trouble trying to negotiate the staircase.
Miguel loves traditional values and likes to wear his sombrero to remind him of his heritage.
Dingbat is a little bat that can't fly. He dreams about the day he might and practices flying all the time. His practice runs often involve gadgets created by him and Marty and usually end in tragic comedy. Marty has organized a rubber band powered toy airplane for him.
Dingbat is a big fan of superheroes, his favorite being "Bat Boy". He often can be found reading Bat Boy comic books over and over again.
Dingbat was featured in Mia's Language Adventure as well as the more recent Mia's Reading Adventure.
The spunky baseball cap donning Scary the Spider is a slightly older, slightly cooler, friend of Mia and Marty. A bit of a trickster, Scary has a preference for a surprise entrance, dropping in whenever he’s least expected, usually with a laugh or snicker as he really likes to startle, and not scare, whomever it is he’s popping in on.
His trickster aspect may also reveal itself in the enigmatic advice he might give the others by way of cryptic clues, riddles, and songs, sometimes funny and sometimes mysterious, often adding to the intrigue of the latest mystery Mia may be trying to solve. Always in the strangest places at the strangest times Scary might be a big help when situations really get urgent. And even if he really can’t do anything to help he might just try to entertain or amuse by singing a funny song, doing a dance or telling one of his silly jokes.