In a strict patriarchal home, Azhagu Malar and Mathi arrive. Their contrasting natures challenge male dominance and bring unexpected change.

Siva is an honest police officer who was brought up by the judge Sathyamoorthy, when his mother died. Sathyamoorthy has two sons : Aravind and Raja. The influential smuggler Mudaliar often clashes with Siva and Sathyamoorthy. Siva and the jolly college student Priya fall in love with each other, later they get married with Sathyamoorthy's blessing. One day, Raja rapes Mudaliar's daughter. The next day, Raja is found dead and Siva conducts the investigation. Ramesh admits to his father Sathyamoorthy that he killed his younger Raja. Sathyamoorthy decides to protect Ramesh at all costs while Siva wants to send Ramesh to jail. What transpires later forms the crux of the story.