100 Sleeping Princes and the Kingdom of Dreams
The Yume Oukoku to Nemureru 100-nin no Ouji-sama anime is based on the otome smart phone game developed by GCREST.
The heroine of this story is invited to a different world called ‘Yume Sekai' (Dream World). She has to go on a journey, where she frees princes who are sealed away in rings, so they can stop the evil Yumekui, who eat the dreams of people.