During a summer, Norimichi Shimada and his companions wonder whether fireworks appear circular or flat when viewed from the side. They devise a scheme to discover this at the Moshimo Festival"s pyrotechnic show. Yet Norimichi becomes torn when his classmate, Nazuna Oikawa, intends to flee home and urges him to accompany her. When their escape plan falters, in the midst of confusion, a mysterious sphere in Nazuna"s hand offers them a fresh opportunity to remain together.
