Hiding My Identity From My Husband

Charles is an imperial spy who enters a fake marriage with an agent from the Holy Kingdom to sabotage his mission without revealing her identity. She deliberately acts obnoxiously to make everyone dislike her, but her plans backfire when she accidentally becomes a hero by exposing conspiracies and helping capture intruders.
To make matters worse, her fake husband, who has always suspected her, begins falling for her and refuses to let her go.