Jong-seok is the secondary main antagonist of the 2010 South Korean film The Man from Nowhere.
He was portrayed by Kim Song Oh.
Jong-seok is the younger brother and co-leader of drug dealer Man-seok's crew. He is more of a psychopathic man-child compared to his brother caring very much about partying, sleeping and abusing women he sleeps with, smoking drugs, and high-end clothing and his maintaining his physical appearance rather than their gang's activities but much more vicious and cruel to an extent. However he works with his brother in bringing down their abusive boss Mr. Oh who they believe is going to end them using the mysterious pawn broker who beat two of their henchmen by leveraging the lives of Hye-jung and daughter So-mi the former who stole drugs from their former boss by making him deliver the sample to Oh as part of a set-up to have Oh busted.
Jong-seok also has Hye-jeong's boyfriend kidnapped as he believes Cha was in on the heroin sample being stolen and assumes Cha is involved in something against them, sadistically interrogating him with an ax and Man-Seok kills him after giving up So-mi to a female child trafficker and accomplice in the boyfriend's kidnapping. Jong-Seok is suspicious about Cha's character while eating with Man-Seok who also reveals he sent their silent assassin Ramrowan to kill Oh and harvest his organs who had escaped the cops.
At a club the brothers bail from a club after Cha (who had not known Man-seok's face) arrives and Ramrowan manages to wound Cha. The brothers narrowly escape from Cha.
Later Cha tracks down a drug manufacturing plant where children are being used to make drugs
and when one dies there organs would be harvested and sold to various parts of South Korea. Cha shoots a gangster in the head and Jong-seok in the leg and tortures him for So-mi's whereabouts who refuses to cooperate and kills him in an explosion after freeing the child slaves.