Mia Guillem is a supporting character in the anime Kaleido Star. She is introduced as one of the first friends of the protagonist Sora Naegino, though initially she and her friend Anna Heart reject Sora. Over time, Mia becomes one of Sora’s closest friends and most loyal supporters. She is a performer at the Kaleido Stage but later discovers her true passion lies in writing and script development. Mia is a talented writer who creates several productions for the stage, including Dracula and Swan Lake, with her first original work being titled Freedom. She also runs a personal website dedicated to the Kaleido Stage, providing information about the show and its performers, and she is known to be a fangirl for celebrities.

Mia’s personality is marked by strength and determination. She tries her best not to disappoint her grandmother, who is her biggest fan. This close family bond occasionally creates inner conflict when Mia must balance her performing duties with caring for her sick grandmother. She is a grounded and supportive friend who, together with Sora and Anna, forms a like-minded trio that helps one another through hardships. Her role in the story evolves from a fellow acrobat to the primary scriptwriter for the Kaleido Stage. In the second season, she faces challenges when director Leon Oswald makes constant changes to her scripts, causing stress and occasionally affecting Sora’s performances. Despite these difficulties, Mia remains dedicated to her craft and finds that her true talent shines offstage rather than on it. She has a keen interest in introducing literature into the circus acts, enriching the Kaleido Stage’s repertoire. Her development centers on discovering her own unique strengths and learning that she can contribute meaningfully without being in the spotlight. Mia is of Dutch background, with a Catalan family name, and she is physically described as having orange hair and blue eyes.