Carmilla is the biological daughter of King Fritz and Queen Isabella of the sky kingdom Cagliostro. Born amid political upheaval, infant Carmilla was concealed from conspirators who overthrew her parents. A loyal palace maid raised her anonymously within the castle walls. Unaware of her lineage, Carmilla lived as a maid herself, forming a deep bond with fellow maid Maria. Her existence remained a guarded secret, shielding her from the knowledge that her parents were imprisoned in the palace dungeons.

The revelation of Carmilla's identity becomes pivotal when Queen Isabella escapes captivity and discloses her heritage during a kingdom-threatening crisis. Initially burdened by her sudden royal legacy and expectations, Carmilla grapples with her past. Confronting imminent destruction, she accepts her role. Demonstrating courage, she directly challenges the primary antagonist. Her public emergence as Princess Carmilla legitimizes the resistance against usurpers, rallying Cagliostro's people to secure the kingdom's future. Following the conflict's resolution, Carmilla formally ascends as Crown Princess.

This character's background, development, and actions are exclusively depicted in the television special "Lupin III: Princess of the breeze ~Kakusareta Kūchū Toshi~".