Vishnu (Thiagarajan) was a clever student but he cannot tolerate cheating at the school exam and beat a professor (M. S. Bhaskar), he was subsequently excluded from the engineering school. He decides to work as a car mechanic. Vishnu and Shanthi (Rupini) fell in love with each others.
His brother Siva (Sarath Kumar) is an honest municipal commissioner. Siva and his wife Lakshmi (Geetha), a jailer, are transferred to the same city where Vishnu lives. They were shocked when Vishnu tells that he is working as a car mechanic.
Kathavarayan (Goundamani), the municipal chairman, and his brother Ashokan (Ratheesh) are corrupted and influential persons. Siva clashes with Kathavarayan and Ashokan. Meantime, Ashokan kills the journalist Raji (Vaishnavi) who sends the details of their illegal works to Siva. Ashokan is later sent to jail. Siva wants also to punish Kathavarayan but Ashokan kills him. The guiltless Vishnu is sent to jail for killing his own brother. In jail, he meets his sister-in-law Lakshmi and his enemy Ashokan. What transpires later forms the crux of the story.