One day in summer, when the cicadas are chirping loudly. Haruka Nanami, a sophomore in high school, receives a confession from Kudo Satoru, a student at a neighboring high school. Haruka is at a loss, saying, "I've never even talked to him before..." Kudo suggests that they start out as friends, and the two exchange contact information. At the same time, at a railroad crossing in the town where the two live, a series of similar accidents occur day after day. They are madly in love. They want to be together, but they can't.