Tomokane is a first-year student in Ayanoi Academy's specialized Geijutsuka Art Design Class (GA-1). She possesses an explosive temperament and a tomboyish streak, preferring fists over finesse to solve problems. This directness defines her art techniques; she relies on forceful methods like varying pencil pressure for shading rather than switching pencil grades. Despite this unconventional approach, she exhibits significant natural artistic talent.

Her combative nature stems partly from a competitive, strained relationship with her physically fragile older brother. He consistently outmaneuvers her intellectually, fueling her frustration and impulsive reactions. Though their interactions involve rivalry and pranks, she demonstrates underlying concern, rushing to his aid during health episodes.

Within her friend group, Tomokane frequently collaborates with Noda Miki on pranks and disruptive antics. Their actions often unintentionally damage artworks, particularly those of the gentle Kisaragi Yamaguchi, prompting Tomokane's later remorse. She displays high energy and impatience with inactivity, though exhaustion sometimes leads to classroom naps. Her development includes moments revealing hidden depth, such as inadvertently creating sophisticated origami during a simple assignment, and a gradual increase in consideration towards peers beneath her brash exterior.