"KL Gangster" follows two brothers who become entangled in the gangster life. After being betrayed by his own group, which was established by Shark (Syamsul), the step brother of Kuala Lumpur's most powerful mobster, King, Malek (Aaron Aziz) was sentenced to five years in prison (Ridzuan Hashim). Malek, who has since returned to a normal life, is drawn back into the world he left behind after all these years. Especially since his younger brother Jai (Adyputra) has been swayed by the criminals and has decided to work for Shark, causing havoc.