The demon king Iblis was planning to rule the world, but he was defeated by a hero and weakened. But after being defeated by a hero, he is weakened and transformed into a young girl. The demon king secretly vows revenge. She changes her name to Iris and sets out on a journey to regain her power. But she is confronted by humans filled with lust and monsters who rebel against her. Will Iris successfully defeat the heroes and take her revenge?