My Name (AT)

Yoon Ji-woo's father dies suddenly. She wants to desperately take revenge on whoever is responsible for her father's death. Yoon Ji-woo works for drug crime group Dongcheonpa. Choi Moo-jin is the boss of the drug gang. With the help of Choi Moo-jin and to uncover the reason for her father's death, Yoon Ji-woo joins the police department and becomes a mole for the drug group. Yoon Ji-woo is assigned to work in the drug investigation unit in the police department. Her partner there is Detective Jeon Pil-do.
Source: https://en.wikipedia.org/wiki/My_Name_(TV_series)