Aoi Harukawa is a reserved 17-year-old female second-year high school student whose kind-hearted nature remains suppressed by severe bullying within her school's caste system. This relentless harassment strips her of social standing and isolates her, leaving her unable to express her true feelings. Her despair culminates in a suicide attempt, revealing the depth of her emotional fragility.

Her ability to see the summer ghost, Ayane Sato—who manifests only to those near death—forges a bond with fellow witnesses Tomoya Sugisaki and Ryou Kobayashi. Joining their search for Ayane's body becomes a pivotal moment, granting Aoi newfound purpose and connection.

This shared journey sparks her transformation: she later confronts her bullies directly, reclaiming agency and demonstrating unexpected resilience. A year after their ghostly encounter, Aoi returns with Tomoya to the abandoned airfield. There, Ryou's spirit appears, urging them to embrace life—a testament to the enduring impact of their collective experience.