Fireworks, Should We See it from the Side or the Bottom?

One summer day, a group of sixth-grade boys have an argument about whether fireworks are round or flat when viewed from different angles and embark on a journey for the answer during the annual firework festival. Meanwhile, one of their classmates, Nazuna, is troubled by her parents' separation and decides to choose one of the boys – Norimichi or Yūsuke – to run away with, depending on who wins a race at the pool.