Konyaku Haki Sare Suterareru rashii no de, Gunjin Reijou Hajimemasu

Celestia, the daughter of a prestigious noble house, is told a prophecy by her step-sister, who claims to be the "Heroine" of this story.

"Sister, your engagement will be annulled, and Father is going to disown you. Your final destination is a convent!"

To avoid this ruinous future that is steadily becoming a reality against her will, Celestia decides to take drastic measures: she apprentices herself to her grandfather, a legendary General stationed in the remote frontier! She resolves to abandon the life of a lady and live strongly as a soldier instead.

...However, for some reason, the Crown Prince she meets in the borderlands has taken a keen interest in her!?