Yusa, originating as an ice devil also known as a yuki-onna (snow woman), features across the *Dropkick on My Devil!* franchise. She sports long light-blue hair reaching her hips and matching blue eyes, typically clad in a very pale blue kimono.

Her core role centers on being the fiercely protective older sister to Kōji, her younger ice devil sibling characterized by a mole-like face and muteness. Yusa demonstrates unwavering dedication to Kōji's well-being, reacting with fury toward anyone mistreating her sister. This protective instinct manifests decisively when confronting Jashin-chan after Kōji experiences bullying, resulting in Jashin-chan being frozen.

While generally presenting a polite and mild-mannered demeanor, Yusa's personality shifts sharply when her family's honor or Kōji's safety is threatened. She openly expresses disdain toward perceived disrespect, highlighting a firm moral boundary tied to familial loyalty. Professionally, she operates as a maker and seller of ice cream and snow cones, leveraging her ice-based abilities.

Kōji's unique physiology—producing strawberry-flavored syrup from her blood and lemon-flavored syrup from her urine—adds a recurring element to their interactions. Yusa's involvement in broader plotlines, such as the *Apocalypse Day* narrative, remains consistent with her established protective role. Her character functions as a stabilizing force for Kōji amidst the chaotic dynamics involving other supernatural beings like Jashin-chan, Medusa, and Yurine.