One day, a crack suddenly appeared in the sky. Magatama (evil spirits) spilled out from it, transformed into demonic corpses using living creatures as vessels, and began attacking the human world. Orbs appeared to counter these, and those who obtained them became Slayers, tasked with protecting this world. Arata, an 11-year-old boy, obtained the jet-black Orb of Soot, which is not one of the five Slayer attributes. An outcast who cannot be assigned to any attribute, Arata honed his power to control soot, which eventually became a weapon that would shake the world.