Unnamed Memory, Vol. 1 (manga)

"My wish is for you to become my wife!" "DENIED!" Witches-the centuries-old mages that command power immense enough to bring catastrophe. Oscar, the crown prince of the powerful kingdom of Farsas, was cursed as a young boy to never sire an heir. Hoping to break the magic, he seeks out Tinasha, the strongest witch on the continent. To meet her, he climbs her tower, as she is said to grant the wish of any who successfully do so. Yet, when he arrives at the top...he requests that Tinasha become his bride!