Shirayuki-hime, called Snow White, hails from the magical kingdom of Phandavale. She serves as one of the Three Musketeers, dedicated to protecting Souta Suzukaze, the "Key" to the scientific world of Elde. Born into a lineage renowned for potent ice magic, Snow White holds the title of her homeland's most powerful ice mage. Her mission demands close cooperation with fellow Musketeers Akazukin and Ibara-hime to guard Souta against the witch Cendrillon and her Nightmarians.

Snow White possesses a youthful appearance, seeming younger than her fourteen years due to a character design featuring oversized, doll-like eyes and diminutive proportions. Her attire consistently reflects her royal status and aesthetic preferences, incorporating modular pouches and accessories even when they prove occasionally impractical in combat.

Her primary combat strength lies in water and ice magic, enabling her to create defensive barriers, manipulate moisture, and launch ice-based attacks. However, she exhibits significant physical frailty, struggling with tasks requiring brute strength without magical aid. For most of the series, her magical capacity remains artificially restricted; she secretly maintains a protective barrier around the human Ringo, continuously expending energy to shield her. This constant drain limits Snow White's effectiveness in battle until the barrier's eventual release near the story's end, which finally unleashes her full potential.

Personality-wise, Snow White embodies refinement and propriety, often contrasting with Akazukin's impulsiveness. She displays pronounced sensitivity to fashion and social decorum, occasionally prioritizing appearance over tactical considerations. Upon arriving in Elde, she develops an immediate and unexplained romantic attachment to Souta, contributing to interpersonal tensions within the group.

Her character arc includes moments of vulnerability, particularly when adversaries manipulate her trust or vanity. Nevertheless, she demonstrates resilience and profound loyalty, especially during the final confrontation with Cendrillon, where her unrestrained magic proves instrumental in protecting allies and countering the witch's forces.

Following Cendrillon's defeat, Snow White returns to Phandavale alongside her fellow Musketeers, parting ways with Souta and Ringo as their worlds remain separated.