Shanmugam (Parthiban), a veterinary doctor, lives in the city with his wife Valarmati (Devayani) and their two children. In school, Shanmugam was in love with his classmate Dhanalakshmi (Nandita Das), but fate had forced them to go their separate ways, with Dhanam being forced to wed her brother-in-law (Sayaji Shinde). One day, Shanmugam spots Dhanam, who, having lost her husband, now lives a life of poverty on the platforms with her son Balu. After an unsuccessful attempt to find her a job in a friend’s house, he hires her as their servant-maid. However, memories of the past start to create a tension between Shanmugam and Dhanam, despite their attempts to maintain a distance.
One day, Valarmati finds out from Shanmugam’s old classmates how they both were in love when they were young, and she starts fearing that Shanmugam will leave her and her children for Dhanam. Valarmati becomes so distraught that she even humiliates Dhanam at a party organized by one of their friends. When they return home, Valarmati confronts Shanmugam, and an argument ensues. Dhanam overhears their argument and silently goes to bed. The next morning, Dhanam and Balu are nowhere to be found. When Shanmugam searches the house, he finds a letter written by Dhanam saying that she wants Valarmati and Shanmugam to be happy and that she doesn’t want to come between them. Soon, Valarmati realizes the truth and wants to bring Dhanam back home and ask her for her forgiveness.