One day, an ordinary girl is summoned to a different realm and is named a princess of the dream world - a place where dreams fuel life. Soon, the dream world is under siege by a malevolent entity known as the "yumekui" (dream eater), causing numerous princes to fall victim to its grasp. The heroine is tasked with awakening the princes, who have lost their dreams and remain trapped in their slumber, in order to rescue the dream world from imminent destruction.