The Kendo Club from Seijou Girls Academy is going to Shoushinji for their summer training camp. A long time ago, a demon eradication mission took place on the island of Urashima, located nearby. They arrive just before a celebration in honor of a god that Urashima reveres. This festival commemorates the onitaiji and ensures that people remain healthy for another year. The weather around Urashima deteriorates, and storms are more likely to occur in the days leading up to the festival.