The world after the last war of humanity. The earth is covered with black forest, and the people have been infected with a human pyrogenic pathogen that causes their bodies to burn when they approach a natural fire. The fire in this world is gathered by hunting black beasts that live in the forest, the Fire Demons. Recently, there has been a rumor whispered among the fire hunters who hunt the Fire Demons. "The fire hunter who hunted the thousand-year comet "Shimmering Fire," an artificial star wandering in the empty sky, will be called the King of Fire Hunters." The protagonists of the story are Touko, a girl who grew up in a village, and Koushi, a former student in the capital city. Their encounter, which was never supposed to happen, changes the fate of the world.