Unusually, this is not a film dominated by a male protagonist. Instead, it chooses to revolve around the life of Sala (short for Visalatchi) played by Sneha, who when the film begins is about to complete her master's degree. Though she is the only daughter of her parents, she always enjoys the company of people. While attending a relative's marriage, Sala happens to see Natesan played by Cheran who too attends the function along with all his family members, who live together as a big joint family. Both the family meet and arrange the marriage of Sala and Natesan. After getting married into a joint family of assorted uncles, aunts and children, apart from her in-laws Sala feels as if the world is under her heels. There she experiences the love and affection of each and every individual of the family and enjoys each day but Natesan often feels that he is not able to spend time with his wife adequately.
One day Natesan brings a news that he is getting transferred to Attakatti with promotion. Natesan feels happy that he would be able to spend more time with her. But Sala does not want to leave the family and move out. After moving out along with her husband from a house full of relatives into a house with nobody to speak to, the loneliness begins to slowly get to her. Natesan being busy in work and day-to-day activities never notices his wife's abnormality. Sala slowly becomes a psychotic, who repairs her fridge, fan and other equipments in her house and calls electrician played by Kanja Karuppu and talks with him, to overcome her loneliness. She then starts recording the various sounds that reaches her ears, like birds chirping, leaves waving in air, in to a tape recorder. This abnormality turns violent when she tries to record a child's laughter, which causes a stroke to the child and the child turns immobile, which frightens Sala. But the child regains its normal state after treatment. Jayaram who comes as a doctor Ramalingam, finds her abnormality and warns Natesan. But it turns too late that Sala unknowingly consumes too many sleeping pills to overcome her loneliness. Then Ramalingam advices Natesan to take Sala back to their joint family when they discover Sala is pregnant. So does Natesan and they lead a happy life.
The most talked part of the film was the filming of the song "Iru Vizhiyo" which showed most of the rituals and formalities followed in a typical chettinad marriage.