Gakeppuchi Reijou wa Kurokishi-sama wo Horesasetai!

My family is in debt, and we don't have enough money for my sick sister's treatment... The troubled noble, Clarice, finds herself engaged in a political marriage with the most feared knight in the kingdom, Frost the Black Knight, known for "slaughtering beasts with his bare hands". In an attempt to secure his family fortune, Clarice tries to seduce the "Black Knight", but just as she does, she discovers "her" secret...