Yakusou Reijou to Mofumofu no Danna-sama Mofumofu Series

Renaldo, the lord of a small country estate, was becoming increasingly desperate. He couldn't find a suitable wife. At age 19, he was tall and handsome, but he wasn't particularly wealthy, was extremely shy, and seemed rather unfriendly—so no one seemed interested in marrying him. Furthermore, Renaldo had a secret: he transformed into a werewolf on moonlit nights. Hoping for one last chance, he attended a royal ball in the capital, where he finally met a noble lady named Meredith...!? (Source: Shueisha, translated)