A long time ago, a battle ensued between God and the Demon Lord. To resist the powerful Demon Lord, God created a human.
Sacrificing his own body to seal the Demon Lord, God assigned the role of guarding that seal to the chosen one. Through an eternity of time, the seal has weakened, and a window to the underworld, "Dark Gates" have appeared in multiple locations.
Monsters start to invade the land. To break free from the doomed fate of man, they will rise and destroy every last "Dark Gate"…