The Seijou Girls’ Academy Kendo Club is traveling to Shoushinji for a Summer training camp. Near there is an island, Urashima, where legend has it a demon extermination took place long ago. They arrive around the time of a festival which honors a god that is worshipped by the people of Urashima; it celebrates the onitaiji and ensure another year of health for the people. Around the time of the festival, the weather around Urashima worsens and storms will come. A few days into their training, Osanai Shouko finds a girl washed up on the shores near the location of the training camp. She cannot speak and doesn’t seem to know much about herself...

The Seijou Girls’ Academy Kendo Club is traveling to Shoushinji for a Summer training camp. Near there is an island, Urashima, where legend has it a demon extermination took place long ago. They arrive around the time of a festival which honors a god that is worshipped by the people of Urashima; it celebrates the onitaiji and ensure another year of health for the people. Around the time of the festival, the weather around Urashima worsens and storms will come. A few days into their training, Osanai Shouko finds a girl washed up on the shores near the location of the training camp. She cannot speak and doesn’t seem to know much about herself...