Since the demons were forced into the forest twenty years ago, they have never appeared in people's sight again, but now they have begun to invade the peaceful lives of the people in the small town. Knight Eugene accepted his father's order and entered the palace to teach the prince swordsmanship to resist the attacks of the demons.
However, after war after war, the demon mage she met told shocking secrets. Where should she go? Should she continue to stay with the prince, or should she understand the mage's words more deeply...