Go Princess Go (2015)

Zhang Peng is a playboy who hits his head as he falls into a pool when he's trying to run away from an ex-girlfriend. He wakes up to find that he's traveled a thousand years into the past but that's not even the biggest problem, he woke up as the crown princess, Zhang Peng Peng, of the dynasty. Hilarity ensues as Peng weighs between trying to get back to his time and leveraging his new female identity to seduce all the concubines and women he can. Did I forget to mention the hot crown prince and his equally handsome brother the 9th prince, who eventually fall in love with her.