A tale of two worlds: above ground (in the sky) and below ground. The "End" has already come to the Earth we live on. However, in an underground world 3000 meters below ground, superhumans (overmen) are fighting to delay that final moment even just a little. Hiiro, a superhuman who has come from the underground world to the surface, struggles above ground to fulfill the 108 wishes left behind by his dead friend Shion.