At fifteen, Aarius finds himself in a replica of Hell’s first floor, forced to fight devils and monsters. As a Mana Manipulator, he naturally resonates with magic, and the overwhelming mana of this realm allows him to grow stronger. What would be a nightmare for most becomes the perfect place for him to hone his abilities.

Outside of this occasional training from his Guardian of sorts, Granville, life goes on. Aarius has to balance school and the growing powers he's starting to get accustomed to. One person keeps him grounded: a girl he meets at school named Kida.

Everything changes when Aarius miscalculates his Omni-Transport circle. The mistake pulls Kida into it, turning their bodies into mist while their souls remain. They awaken inside a massive labyrinth filled with monsters that require more than strength to survive. But with this new change in circumstances, he gains a skill he was never meant to acquire, yet destined to by Fate