Earth Clear, a world of swords and magic. In this world, people are born with a level and a predetermined role. Warrior, Monk, Priest, Mage, Thief, Merchant, Hunter, Shaman, King, Sage, Hero. And the most populous, powerless, and weakest role of all, the "Villager". One day, a villager and their child are attacked by a monster. A young man suddenly appears, effortlessly defeating the monster, astonishing the parent and child. "Koji Kagami, Villager... Level... 999!?" Koji Kagami, a villager who has reached the pinnacle of Level 999, defies his predetermined destiny. Alice, the daughter of the Demon Lord and the leader of the demons. The two meet and together with their companions, they strive for a world where demons and humans can coexist. In a world where they are fated to be in conflict, What is the secret of this world that awaits them?