Ryo Kobayashi, a high school student, forges a connection with Tomoya Sugisaki and Aoi Harukawa online, united by their shared fascination with the local Summer Ghost legend. His terminal illness forces him to abandon basketball, fostering an initial sense of resignation and isolation. This condition also grants him the unique ability to perceive Ayane Sato, the ghost visible only to those nearing death.

His illness shapes a pragmatic and sometimes withdrawn demeanor, occasionally leading to frustration with others' problems. When Tomoya seeks help locating Ayane's body, Ryo initially refuses, bluntly asserting Tomoya cannot grasp his physical and emotional burden. Comfort from Aoi, however, prompts him to join the search, marking a shift toward collaboration.

Following the resolution of Ayane's story, Ryo voices a final wish: to witness the arrival of spring. He achieves this goal before succumbing to his illness. One year later, his spirit returns to the abandoned airfield where he first encountered Ayane. There, he encourages Tomoya and Aoi to embrace their lives fully, demonstrating his acceptance of mortality and desire for his friends to find purpose.