I recommend "The Cute Concubine of a Concubine: The Black-bellied Prince's Defiant Favor". The female protagonist in the book is a concubine's daughter. She disguises herself as a man and enters the palace. The male protagonist mistakenly thinks that she is a male brother. Later on, she even becomes the male protagonist's concubine. However, the female protagonist still dresses like a man. The female protagonist had many pursuers, including the male protagonist. The prince was addicted to spoiling her, and it was full of sweet love and thrilling twists. I hope you like this fairy's recommendation. Muah ~😗