Lady to Queen

"I will never love the Emperor." My sister Nilla, who became the Emperor's Queen after having dreamt of fairy tales and true loves, came back divorced and accused of high treason. Our family, the Rochesters, was mercilessly executed. But by some miracle, I came back in time, before Nilla was selected as the Emperor's Queen candidate. If I become queen in your stead, you and our family need not suffer. This life of yours can have a happy ending, sister. I promise. (Source: comico, translated)