Koutarou Makimura is determined to confess his feelings to Serizawa Kaho, who appears distant and unapproachable. However, his plans are disrupted when he meets a mysterious girl on the eve of his confession, transporting him into the future. In this future, Kaho is not only his girlfriend, but she has also tragically passed away. Determined to change fate, Koutarou returns to his present time to alter the future and save his beloved.