The Mysterious Bodyguard

Gu Ai, the prime minister's daughter, had been a careless free soul under his father and brothers' protection until the day her father was framed and her loved ones were exterminated for treason. To find out about the truth and seek revenge for her family, Gu Ai disguises herself as a man and becomes the second prince's bodyguard. However, before the truth comes to light, the aloof and scheming prince seems to have fallen for her.