Akumeitakai Ryoushu ni Totsugu Koto ni Narimashita ga Mainichi Shiawase desu

Diana, the daughter of a baron, loses her fiancé to her sister-in-law, who was doted upon by her parents and raised to be selfish. She becomes the laughing stock of society, and marries into the famously violent and cruel Count Wolfgang of the Frontier. But he is not all he is cracked up to be...? This is a Cinderella story about a girl with an unhappy background who finds happiness!