Kon'yaku Hakisareta Koushaku Reijou wa Reijou no Kamen o Nugisuteru

After being publicly dumped by her fiancé, the Crown Prince Lombard, the duke's daughter Christiana appears unshaken. Despite being educated to be a refined noblewoman and the perfect queen, she has always harbored a different dream—to become Lombard's knight. Now, with the engagement off, she finally has the chance to pursue her true calling.

(Source: Manga UP! Global)