Makoto Itou develops a crush on his classmate Kotonoha Katsura after seeing her on the train each morning. Encouraged by Sekai Saionji, Makoto gathers the courage to speak to Kotonoha, beginning a fragile and awkward relationship.

Sekai helps Makoto and Kotonoha grow closer, but her own feelings for Makoto deepen. Emotional boundaries blur as Makoto struggles to understand what he truly wants.

Makoto grows distant from Kotonoha while becoming closer to Sekai. Rumors spread through the school, and jealousy begins to take hold among their classmates.