The Demon God has abducted the princess Misa, intending to sacrifice her to restore his waning power. The king dispatched an army headed by a knight carrying the legendary Sword of the Valiant—but every soldier fell, and the knight himself delivered a fatal blow to the Demon God only to be mortally wounded in return. With no army and no knight left standing, Princess Misa picks up the Sword of the Valiant herself. Her only path home runs through a dungeon filled with deadly traps and the Demon God's remaining servants.