100 Sleeping Princes and the Kingdom of Dreams

The story follows an ordinary girl who becomes the princess of a world where dreams are used as a source of energy. In this world, known as the Kingdom of Dreams, people's dreams are being consumed by creatures called "yumekui" or "dream eaters," which are attacking many princes, leaving them in a state of deep sleep. The protagonist must find and awaken the affected princes, as they are unable to wake themselves due to their stolen dreams.