Prabhu Ganesan, Kushboo Sundar, Manorama
he movie starts with the birth of a baby girl, Nandini, in a rich family. Nandini's three brothers throw a feast in honor of the girl child. The young son of the local singer (who had died) is brought in to sing for the event. The three brothers raise Nandini like their own child as their parents had died. At the age of 5, an astrologer predicts that Nandini will bring much happiness to the family, but her marriage will based on her choice and not the choice of her brothers. This angers the brothers and to prevent this from happening, she is raised within the confines of the house.She is home schooled and when she does go out, all the men are warned to hide from Nandini and that seeing Nandini will be met with dire consequences.
Nandini Kushboo reaches puberty. The few males allowed around her are the service staff and her bodyguards.Meanwhile, the boy who sang, Chinna Thambi Prabhu grows up to be a naive and gullible simpleton with a heart of gold.He is raised by his widowed mother Manorama. He doesn't go to school and spends his time singing and entertaining the people of the village.
One day the bodyguards get into a fight with Chinna Thambi who kicks their asses. Impressed with Chinna Thambi's naivety and fighting skills, the Brothers hire Chinna Thambi to be Nandini's bodyguard and butler. Nandini meanwhile starts to resent her lack of freedom. She engages Chinna Thambi to show her the village without her brothers knowledge. Chinna Thambi complies with her wishes and shows her the village which results in Nandini getting sick. Chinna Thambi is blamed for Nandini getting sick and gets beaten up by the brothers. Nandini who has just started to like Chinna Thambi feels guilty for being the reason for him getting trashed. She shares her medicine with Chinna Thambi who inadvertently equates Nandini to his mother, as being the few people who truly care for him. This incident brings them closer together emotionally.
One day, a factory worker is punished for leering at Nandini. He plots to kill Nandini at the inauguration of the new factory owned by her brothers. Chinna Thambi overhears the plot, and in a desperate attempt to save Nandini lunges on her and inadvertently feels her up in public. Nandini doest mind and defends Chinna Thambi by arguing that Chinna Thambi wouldn't do something like that in public. But her brothers are enraged.They beat him to the point that they almost kill him. Nandini stops them and gives him a chance to explain.When Chinna Thambi explains the situation they hang their heads in shame. Chinna Thambi quits his job on the spot, despite Nandini's silent apology. That night Nandini decides to meet Chinna Thambi and apologize and perhaps convince him to come back to the job.Chinna Thambi refuses to come back as he doesnt want to put up with the violent nature of her brothers. She thinks if Chinna Thambi marries her, they wont be able to manhandle Chinna Thambi. She convinces Chinna Thambi to tie a mangal sutra around her neck which will protect him from her brothers. Chinna Thambi without realizing the sanctity of the act does as told and doesn't realize he is now married to her.
Chinna Thambi comes back to work and is given a higher level of respect by the brothers for saving Nandinis life. Nandini too starts emulating her sisters in law in taking care of her husband. This makes Chinna Thambi nervous but he still remains clueless.Her change in behavior is noticed by her sisters in law who urge the brothers to get Nandini married off before the situation gets any worse. Nandini realizing that they are trying to get her married off tries to make Chinna Thambi understand that they are already married. Chinna Thambi refuses to understand and runs away to his mother who upon realizing what has happened pulls him out of denial.She sends him away in an attempt to protect him.
The brothers come to know whats happened and try to torture the mother to get her to reveal where her son is hiding. She is saved in time by her son who almost kills the brothers. The wives of the brothers stop him from killing them and ask him to save Nandini who has upon hearing the torturous acts of her brothers has now resorted to self destruction. Chinna Thambi rushes back to save his wife and revives her with his singing. Nandini runs towards him in slow motion and the movie ends with them embracing, with her brothers finally supporting their relationship.