Ore-sama Outaishi ni Hirowareta Gakeppuchi Reijou, Okazarigawa Hi ni Naru... Hazu ga Dekiaisaretemasu!

Beatrice was living modestly as a translator on the side. Her best friend betrayed her, and her engagement was suddenly broken off, leaving her in a precarious position. If things continued as they were, she would lose the title her family had protected... The one who saved her from this dire situation was Crown Prince Alfred, whom she'd never met before...?! For some reason, he suddenly declared Beatrice "my wife" and, in return for her help, appointed her "aide and figurehead consort." Using her magical powers and translation skills, Beatrice discovered a secret about the country, leaving her with nowhere to run. Using her natural cheerfulness and energy, she struggled to fulfill her duties and be of service to everyone... But then, the egocentric Crown Prince, whom she'd always disliked, began to dote on her with excessive affection...

Wait, I'm just a figurehead consort, right?!

(Source: Akita Shoten, translated)