Roni, an orphan who grew up misunderstood as a boy. One day, she is chosen by a high-ranking nobleman who comes to the orphanage. To pretend to be a male young master. The moment they found out that I was a woman, I would be sent back to the orphanage. I promised myself that I would be careful and survive. "You Are you a girl?" It was caught in one day! The truth was revealed as I stood in front of the Duke. "No way" Was I going to be kicked out like this, or was I going to be severely punished for deceiving a noble? I was so scared that I begged and admitted my mistake. "Oh, you look like a doll!" "You! Be my little sister, not my playmate!" Instead, they greeted me kindly? "I can't because you're too cute!" The story of Roni's life in the Duke's castle, who was forced to stay because of her cuteness!