A noble king who is most respected in this country hides the fact that he is actually a vampire the king has 4 sons, all the princes have vampire blood from their fathers, all the palaces hide this reality from the public, all pretend to be ordinary people, but at night everything is tense They need blood, it is always provided secretly in the palace by the palace servants The first prince is named Seungcheol, a handsome prince with a cold and firm aura second prince named Jeonghan, handsome prince who is mischievous and kind The third prince is named Wonwoo, a handsome prince who is quiet and shy while the fourth prince is named Mingyu, a handsome prince who is flamboyant, cheerful and friendly Until one day, you are an ordinary girl from the human race who is employed in the palace for some reason