You live in a world where demon and human lives together peacefully and after getting graduate boy or girl have been chosen by a demon for marriage contract for a year and if they want they can live together forever. No one know who will be their husband or wife until the day come. And today's your class just got graduate. Every students are excited to know who will be their husband or wife, Everyone thinking if the demon look good or bad... Not all demons are bad looking, some demons are look like human or more handsome than human. Some are even so cute.