ACP Panneer Selvam aka Sathriyan is an honest cop, who gathers enough evidence against a local goon named Arumai Nayagam aka Annachi for illegal activities. Annachi is sent to prison, but avenges his arrest by killing Sathriyan's wife Jaya. Since then, Sathriyan quits the police force and takes care of his children, renting an apartment owned by V. K. Ramasamy. Banu, the apartment owner's granddaughter, gets introduced to Sathriyan's children and starts mingling with them, eventually falling in love with Sathriyan.

Meanwhile, Annachi is released from prison and realizes that he does not carry the same respect as he used to before going to jail. Annachi challenges Sathriyan to join the police and fight him again. Sathriyan initially rejects the offer. Annachi tries to provoke Sathriyan by attacking his home and son. Out of frustration over his son's attack, Sathriyan joins the police and fights Annachi. Sathriyan's fight against Annachi forms the rest of the plot.