Aya is a high school classmate and sole female friend within a trio of delinquent protagonists, engaging directly with the group to challenge their antics and offer blunt critiques. Her involvement includes attending their fledgling musical gigs, where her skepticism about the band’s provisional name sparks its permanent adoption.

She clashes persistently with the group’s leader, confronting his indifference toward their musical ambitions in a bid to instill dedication. Tensions peak during a fiery argument where she leaves in frustration, only for him to pursue and abruptly seize her arm—a provocation she counters by slapping him.

After the band’s festival performance, the leader confesses the group’s disbandment to Aya in a deserted classroom, then unexpectedly invites her to join him elsewhere, implying lingering tensions. A witness notes their exchange but withdraws discreetly.

Aya’s portrayal blends tolerance with assertiveness, positioning her as an anchoring force who voices blunt disapproval of the trio’s choices without abandoning their orbit. Her pragmatic resolve starkly counterbalances the protagonists’ recklessness, underscoring her role as both critic and committed ally amid their turbulent endeavors.