Mayrie is an original character exclusive to the anime adaptation, absent from L. Frank Baum's source material. She acts as a close companion to Claus during his formative years, characterized by notable enthusiasm and occasional displays of temper, reflecting a spirited personality. Narrative subtext implies potential romantic feelings toward Claus.

Functionally, she assists Claus in toy-making by coloring his creations and actively participates in his adventures, sharing various challenges and experiences. Her presence introduces interpersonal dynamics unexplored in the original literary work. Her background, origins, and character development remain unspecified, with no details regarding appearances in spin-offs, films, or OVAs. Her role is confined to the main narrative as a humanizing influence and collaborative figure in Claus's early life.