Realistic and socially relevant, this action drama revolves around a brave young man Velu Thondaiman, affectionately known as "Thambi", who fights against all types of evils in the society. In the process, he keeps running into Sankara Pandian, a political henchman who rules the city with violence. Thambi is determined to defuse Sankara Pandian's anti-social and criminal agenda, and his fearless attitude brings fear into the members of Sankara Pandian's gang.
Thambi thwarts Sankara Pandian's terror plans with the help of his close associates. Then, a flashback unravels how Sankara Pandian's gang kills Thambi's family after Thambi brings to justice Sankara Pandian's brother Saravana Pandian.
As police dispose off his thugs by means of "encounters", Sankara Pandian starts riots within the city to topple the internal government, so he can achieve power as a member of parliament. But, in the riots, Sankara Pandian's daughter and mother are caught and Thambi saves them single-handedly. Sankara Pandian is touched by Thambi's selfless nature and turns a new leaf, but, his brother Saravana Pandian is released from prison and he is out to avenge Thambi. How will life turn out for the soldier of justice, Thambi?