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 to run away with.

A young man kills his bride on the day of his marriage and goes insane. He wakes up in an asylum with no memory, left in the hands of two mysterious doctors who relate his condition with his biological identity.