Shiva a happy-go-lucky guy helps two of his best friends get married, much to the dismay of their parents. When the girl gets raped by Madan, Shiva and his friends seek to bring him to justice.
Shivaraj aka Shiva is a college student who lives with his widowed mother and sister. His friend Sundar is in love with their classmate Priya, but Priya's rich father opposes their relationship. Shiva helps Sundar and Priya to elope. Meanwhile, Sneha, the daughter of ACP Chandrabose, falls in love with Shiva. Initially, Shiva rebuffs Sneha, but eventually, he reciprocates her feelings.
Madhan, the son of a powerful rowdy politician Desigan, is a notorious womaniser who lusts for Priya. He gang rapes Priya in the college library and then kills her. Shiva, Sundar and their friends decide to avenge her rape and death by their own brand of justice i.e. killing Madhan, only to be stopped by Chandrabose, who prefers to arrest Madhan and let the court decide his punishment as he does not want Shiva to end up as a criminal. A cat-and-mouse game begins between Shiva and Chandrabose regarding Madhan's fate, which culminates with Chandrabose arresting Shiva, to protect him from Desigan and his men, who are planning to kill him, while Madhan is arrested as well.
Desigan hires a corrupt lawyer Killadi Krishnaswamy to fight Madhan's case in court. Krishnaswamy, using crooked tactics, manages to acquit Madhan of the rape and murder charges. Meanwhile, Desigan kills Sundar as well as Shiva's mother. It is at this stage that Shiva and Chandrabose team up and plan to eliminate the trio (Madhan, Desigan and an unknown third person). Chandrabose hires Krishnaswamy to fight for Shiva in the court and acquits him of killing the three men, and then takes Shiva's place in jail. Shiva kills both Madhan and Desigan. At the court, Krishnaswamy manages to acquit Shiva by claiming that he is "mentally unstable", despite Shiva's pleas to judge Ganapathy to convict him.
After the verdict, Shiva exposes the "third person" as none other than Krishnaswamy and kills him in front of Ganapathy for his corrupt activities. But he is sentenced to only six months imprisonment. Following his release, he reunites with Sneha and marries her.
