Secret Reunion / Sworn Brothers (Jang Hun / 2010)

Ji-won is a North Korean resident spy, is contacted by an agent "Shadow" and begins a mission to assassinate a traitor. Hot-tempered South Korean intelligence agent Han-gyu gets to know such plot from a liaison and attempts to prosecute "Shadow" without permission but fails. As a result Han-gyu resigns from the agency. 6 years later, Han-gyu operates an investigation agency and come across Ji-won once again. Wanting the bounty for bringing in a Ji-won, Han-gyu offers him a partnership to keep him close. Ji-won assumes that Han-gyu is still the agent and agrees to get rid of his false accusation of a traitor. As they work and live under one roof, they maintain a tight-rope tension but an unusual friendship.

Sunairi: A great Song Gang Ho film that I haven't been able to see his recent films lately.  What a character he can play.  What a emotion and compassion.  This is how good Korean films can get.