Kamishiro Nao, a dropout from his high school's athletics club, confesses his feelings to his senior and club manager, Koga Sachi, but is turned down. In despair, he wishes for the end of the world. Soon after, the Koushin singularity disaster strikes and annihilates the small town where Nao and Sachi live.
After surviving the disaster unscathed, Nao and Sachi struggle to escape the disaster zone, which has mysteriously been geographically and temporally separated from the rest of the country. They rescue four other survivors along the way, with Nao and Sachi developing superhuman abilities to defend themselves against the monsters that prey on the surviving humans in the disaster zone.
An attack by the monsters on one of the evacuation zones eventually provides the six survivors with an unexpected escape route, but Yuuri is separated from the others. The five remaining members try to find him but instead discover a modern metropolis over the hills surrounding their valley town that has been untouched by the disaster...
[Translated from the official website and prelude chapter from the demo]