This Girl Is a Little Wild

After he was defeated, the Demon King used the last of his strength to trap the captain of the Holy Knights into the body of a weak girl. However, the Captain was a girl, to begin with, so, tired of her former life and unable to return to her former body, she decides to live a luxurious life instead, in the body of the noble daughter she's trapped in. However, her new family puts her in danger, so she tries to go to the church to prove her identity. In order to do so, she ultimately becomes engaged to the captain of the special task force. Will she be able to prove her identity and still live an ordinary life? What will happen to her relationship with her fiancé? And, is there something more to this new life she's received?