Uki Sawatari is Kohane's childhood friend and classmate, constantly vigilant about Kohane's safety due to Kohane's self-sacrificing nature. Her pragmatic and realistic personality makes her the natural "tsukkomi," countering Kohane's impulsiveness.

She has blonde hair styled shoulder-length with a side ponytail on the right, shifting to a full ponytail for cheer activities; her bangs are parted to show her forehead. Notably, she always wears a jacket over her school uniform, even in summer.

Her family includes a doting mother and a younger brother, Akane, an elementary student who dislikes "girly" things. To preserve her relationship with Akane, Uki hides her cheerleading involvement. She later confronts his misconceptions when the Cheer Association performs at his soccer match, contributing to his team's victory with her support.

Initially hesitant about cheerleading despite backing Kohane's club idea, Uki joins after seeing Hizume's demonstration. She becomes a founding member of the Cheer Association, later upgraded to a club. Her athleticism suits the physically demanding backspot role, where she enthusiastically supports Kohane during stunts, often involving close contact.

Beneath her stern exterior, Uki harbors a fondness for cute things like idols and clothing, though she feels embarrassed by these interests. She also possesses a significant fear of ghosts. Her protectiveness of Kohane sometimes manifests as jealousy when others get close, and she readily apologizes for Kohane if Kohane offends someone. This dynamic occasionally paints Uki as an overbearing mother figure, though she is comfortable with being perceived as part of a romantic couple with Kohane.

Her development involves balancing her supportive cheer role with personal challenges: reconciling her interests with her brother's expectations and managing her protectiveness of Kohane. She appears in all 12 episodes of the anime adaptation and is a playable character in the mobile game *Kirara Fantasia*.