Plot
Shanmugavel, a corrupt and influential politician, is operating with impunity, and even the police can't touch him for his crimes. His son Bhaskar is spreading terror among college students and professors, doing dirty work like killings for his father's illegal trades. Bhaskar attempts to kill honest minister Deivamurugan by implanting a bomb, but it ends up killing another politician instead. Bhaskar's men then direct the minister to hoist a flag, and despite the tight security provided by honest police officer Eswarapandiyan, they manage to kill the minister.
Meanwhile, Dhamodaran "Dhamu" is selling black cinema tickets alongside his friends Sethu and Vicky. Dhamu is known for being an angry man who frequently fights with the government for basic amenities in his slum. Jothi, Dhamu's neighbour, is in love with him, but he doesn't reciprocate her feelings. Mahalakshmi "Maha", an orphan, moves into the house opposite Dhamu's and joins as a lecturer in the college where Bhaskar is causing trouble. Bhaskar verbally humiliates Maha on her first day, while Dhamu develops feelings for her. When Dhamu comes to drop Maha off at college, Bhaskar and Dhamu clash, and Bhaskar sends his goons to attack Dhamu. However, Dhamu subdues them all. Dhamu's mother, Vellaiyamma, asks him to leave violence, and he promises to do so.
Dhamu then attempts to propose to Maha, and she expresses her desire for a husband like him. Inspired, Dhamu leaves his black ticket-selling business and mends his ways, impressing Maha. He starts working at a two-wheeler mechanic shop. As Dhamu and Maha's love grows, Jothi sacrifices her love for Dhamu and decides to marry another man. Eswarapandiyan confronts Shanmugavel, determined to arrest him for the brutal rape and murder of a girl. In retaliation, Shanmugavel brutally kills Eswarapandiyan's wife, Uma, in front of him. Shanmugavel spares Eswarapandiyan's life but cuts off one of his legs, intending to intimidate other police officers. Meanwhile, Bhaskar loses the college's chairman election and mistakenly assumes that Maha motivated students not to vote for him. Seeking revenge, Bhaskar announces that he'll publicly molest Maha. Fearing Bhaskar's wrath, Maha takes a few days' leave from college. Unable to share her fears with Dhamu, who has promised his mother to avoid violence, Maha considers leaving town.
However, Dhamu stops her and decides to fight Bhaskar, supported by his mother, Vellaiyamma. When Bhaskar and his henchmen arrive to molest Maha, the corrupt police officer removes Dhamu from the scene. Vellaiyamma tries to protect Maha but is beaten and pushed into a sewer. In a desperate bid to protect her modesty, Maha sets herself on fire. Dhamu escapes from police custody and rushes to the scene, only to discover the dead bodies of Maha and Vellaiyamma. Consumed by rage, Dhamu brutally beats and kills Bhaskar by suffocating him in the sewer and burning his half-dead body. Dhamu is later arrested by the police and subjected to torture in custody. Shanmugavel taunts Dhamu, challenging him to kill him. However, Eswarapandiyan saves Dhamu from police custody, and they team up with others who have suffered at Shanmugavel's hands. Together, they start detonating and ruining Shanmugavel's illegal properties. Shanmugavel seeks protection from the DGP, but Eswarapandiyan kidnaps the DGP at gunpoint and confronts Shanmugavel at his industry.
A violent shootout ensues between Dhamu and Shanmugavel's henchmen, and Dhamu manages to overpower them and hold Shanmugavel captive. Dhamu questions the police about whether a corrupt and influential person like Shanmugavel would be punished by the law, but the police remain silent. In the end, Dhamu kills Shanmugavel in public, avenging the deaths of his mother and lover, Maha. Simultaneously, Eswarapandiyan shoots Shanmugavel, avenging the death of his wife, Uma, and the mutilation of his leg.
