Fireworks 2017

During summer vacation in a seaside town, classmates are excitedly debating whether fireworks look round or flat when viewed from the side. Amidst this, Norimichi's crush, Nazuna, learns that her mother is getting remarried and that she will have to transfer schools. Nazuna invites Norimichi to escape the town with her, but her mother catches them and brings her back. Unable to save Nazuna, Norimichi, out of frustration, throws a mysterious ball that Nazuna found at the beach. Suddenly, time rewinds to before she was taken back.