Forget That Night Your Majesty - Season 1

Lunia, the daughter of the Count of Persephone, is chosen by a priest to be engaged to Hades, the head of the Duke of Khronoa family. The Duke of Khronoa, feared as the 'King of the Underworld,' is cursed with a short lifespan if he does not marry a bride chosen by the emperor. However, Hades tells Lunia that he has no intention of loving her. In order to keep Hades alive, Lunia deceived him and spent the night with him, then disappeared without realizing that she was pregnant with his child.