Rocket Raja is a pickpocket in Chennai who steals anything he comes across with his partner Kaatu Poochi. He enjoys his life to its fullest and goes to rob in a marriage function. There he meets Swetha and gets sexually aroused to her and pinches her hip ,to which she reciprocates. However, his life changes when a small girl named Divya Rathinavel ends up in his care; he looks exactly like her father, DSP Rathinavel Pandian IPS.

As Raja discovers the girl's past, it is revealed that Rathinavel is an honest policeman who is a nightmare to criminals, but the gang of criminals in the village of Devi Pattinam, Andhra Pradesh are intent on killing him and his daughter because he killed the son of a prominent criminal Bavuji, who also sexually abused women. Rathinavel's colleagues put Divya in Raja's care so that the criminals cannot take her. Rathinavel is on the verge of death following a gunshot to his head.

At first, Raja is angry with Divya and breaks her tape recorder. Divya is happy and hugs him after he repairs it. When Swetha comes to Raja's home with her parents, she sees Divya and thinks that she is the daughter of Raja and breaks up with him. Rathinavel is intent on fighting back. Unfortunately, he dies following a battle with several criminals who had been chasing Raja and Divya. From police officers, Raja realises that Rathinavel was an honest and courageous police officer who stood against Bavuji and his family, who had cruelly ruled a village. Rathinavel even manages to make his son die and stops their criminal acts. He also manages to fail Bavuji's brother Badra, but he gets shot when he tried to save a child.

Upon seeing his courage, Raja, with the help of Rathinavel's colleagues, steps into Rathinavel's shoes and finishes his unfinished work as he himself is a thug and destroys all their properties with the help of Kaatu Poochi in a hilarious way. There Swetha sees Raja, but he tries to escape from Swetha because he is now Rathinavel, so Swetha seduces him to which he tries to control himself in vain .She apologizes to him on learning the truth about Divya & her father Rathinavel and they reconcile.Raja then resumes his mission and goes on to kill Badra and takes on the responsibility of taking care of Divya, with the help of Swetha.