I Became the Protagonist’s Secret Friend in a Romance Fantasy

I possessed the body of an assassin who serves as the personal attendant of the Northern Grand Duchess—the protagonist of a romance fantasy novel. With no interest in assassination and desperate to survive her awful temper, I spent our childhood convincing her that I was her “secret friend.” But now she insists she needs no one else, questions every new friend I make, and even claims secret friends should have no secrets between them... It seems my gaslighting worked a little too well.