Majo to Ouji no Keiyaku Jouji

Evelina, a rare and powerful witch, successfully brings the slain Prince Demetrio back to life. However, for his resurrection to be truly complete, the act of sex between the prince and Evelina is required!? With secret feelings for the prince, Evelina agrees to spend one night with him, thinking it will be a one-time affair. But the next day, the prince declares that he will marry her to take responsibility! On top of that, due to the cost of the magic, Evelina must continue having sex with the prince for several more decades...!?