In a world where warriors are chosen to wield a holy sword and defeat the Demon Lord every hundred years, Kariel is only a guide, bound to support others from the sidelines. He dreams of rising beyond his rank, but the Demon Lord of this era has already been slain. Despite this, the world begins to unravel instead of heal. Monsters grow unpredictable, a mysterious knight hunts champions, and secret organizations move in the shadows. Traveling with his childhood friend Reina, Kariel is drawn into a dangerous mystery that may determine the fate of the world.