Ayumu Tsutsumi, Hanabi Ayase's childhood friend, re-enters her life after returning from Tokyo. He immediately declares his intention to become her boyfriend, positioning himself as a romantic rival to her current partner, Yuuto Takao. His reappearance complicates Hanabi's existing relationship, fueling a central love triangle dynamic that unfolds across the series. Ayumu appears in all episodes of both seasons. Specific episode titles like "Triangle," "Rival," and "One-sided Love" directly highlight storylines driven by his romantic pursuit and the resulting conflicts. As a supporting character, Ayumu's role centers on his unrequited feelings for Hanabi and their shared history as childhood friends, a past that contrasts sharply with her newer relationship with Yuuto.