City of Fathers (2009)

Kang-su is an alcohol and a chronic gambler. He has also never been a proper father to his rebellious teenage son Jong-cheol. For 18 years, Kang-su has also held a secret from Jong-cheol - that he's not his actual biological father. Jong-cheol's real father, Tae-sok , is a pimp that abandoned love for success. Now, to save his son, Kang-su must go to Tae-sok.