City of Fathers

Kang Su is an alcoholic 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...
(Source: AsianWiki)