Kawaii Gimai ga Kon'yaku Haki Saretarashii node, Ima kara "Orei" ni Mairimasu.

Synopsis:

Beloved by all, Rozelia is the nation’s most gifted talent, excelling in both literature and military strategy. Today she marries her childhood friend and love, Robert, heir to a duchy. Everyone celebrates their union, certain they will live happily ever after. But that night, Robert’s sister, Margaret, bursts into the mansion in ruins. Once engaged to the crown prince, Margaret has been falsely accused, cruelly abandoned, and subjected to horrific treatment. Outraged by the prince’s selfishness, Rozelia cannot stand that Margaret—who had always fixed his blunders—is treated so shamefully.