Akujo wa Utsukushiki Kemono no Ai ni Saku

Falsely accused and branded a villainess, Marquis Karina is married off to Noct, a notorious misanthrope known as the Beastly Count, through her stepmother's machinations. Karina, with her infamous reputation as a villainess, is not welcomed, and all the servants treat her coldly, but only Noct respects her and treats her kindly...! The unfortunate young lady is loved so passionately and sweetly that she melts with emotion, and blossoms into a magnificent beauty—a superb love romance between the Beastly Count and the villainess.

(Source: Flex Comix, translated)