Humanity has been forced to live underground, like moles, to avoid the savage monsters that roam the surface – creatures that are invulnerable to every weapon made by man. The only hope for those below are the Ayanashi – the only ones with the power to defeat them.
In one such subterranean city, a pair of siblings discover a battered and bruised boy named Holo. As they get to know him in the ensuing days, Holo slowly reveals his background. However, the city is soon attacked by a monster from above that destroys everything in its path. Holo steps forward to confront the beast, wielding a flaming short sword that’s fused to his right arm. And so begins the tale of how light can once more brighten an eternal darkness.
