Makoto Ito is a Japanese high‑school student who begins his second term at the fictional Sakakino Academy. On his daily train rides, he becomes infatuated with fellow commuter Kotonoha Katsura. When his new classmate Sekai Saionji learns of his secret crush, she helps introduce the two, and over time Makoto and Kotonoha grow closer and agree to date. Despite her triumphant matchmaking efforts, Sekai inadvertently becomes jealous, as she has also developed feelings for Makoto. The following afternoon, on her way home, Sekai stops at the train station near the school and finds Makoto...