Shirayuki-hime is one of the three legendary Fairy Musketeers from the magical world of Phandavale. Her mission is protecting Souta, the human "key" linking Phandavale to the scientific world of Elde, from the witch Cendrillon and her Nightmarian army. As a master ice mage, she commands formidable water and ice-based magic in combat, specializing in defensive barriers and elemental attacks. However, limited physical strength defines her as a "Squishy Wizard," reliant on magical prowess. Initially portrayed as proud, reserved, and fashion-conscious, her character evolves significantly through interactions with Souta and fellow Musketeers Akazukin and Ibara-hime, undergoing a "Defrosting Ice Queen" arc from aloofness to deeper camaraderie.

A critical concealed handicap exists: she secretly maintains a protective barrier on the human Ringo throughout much of the series. Releasing this barrier in the final episodes unleashes her full magical potential, revealing previously restrained power. Her design features signature large glasses; she removes them during intense moments, impairing her vision, and sometimes uses this tactically to deceive enemies. Her backstory connects to Phandavale's lore, reimagining classic fairy tales into powerful guardians rather than passive figures. Following Cendrillon's defeat and the worlds' stabilization, she returns to Phandavale with the other Musketeers, parting ways with Souta and Ringo in a bittersweet conclusion.