Ten years ago, the hero and his friends succeeded in defeating the Demon King and save the world, however, they never came back was believed to have been dead. However, now, the monsters began to attack humans and kidnapped them to the Demon King's territory. Yuria, the current Hero, led his army on a march into the Demon's territory, in hope of rescuing the captives and to seek the truth behind the rumor of the Demon King's resurrection, however, what awaits them there was something lot more sinister than any could've ever imagined.