The world is split between a kingdom of light in the sky and a kingdom of darkness on earth. As the King of Darkness devotes himself to war, monsters ravage his lands. A boy whose village was destroyed by monsters questions the king's rule.

The monstrous Bahl attacks the Kingdom of White, indiscriminately slaughtering all in his path. While Iris rushes to intercept him, the Prince of Darkness begins his training to become king far below in the Kingdom of Black.

In the Kingdom of White, Iris reflects on her duties and the events that led her to become queen. Meanwhile, in the Kingdom of Black, the Prince of Darkness enters a competition to make his position as heir to the throne official.