Ajay (Shiva), an educated youth comes to Chennai from his hometown Theni to take up a job. Anjali (Priya Anand), a photographer from London is also in the city to capture the south Indian culture.
They both get cheated by Narayanan (Santhanam), a house agent, who rents out unoccupied houses without the knowledge of the owners. Ajay and Anjali pay the money to Narayanan and end up getting the same house. They both are caught in a situation when they are unable to rent a new house. The duo decides to stay together until they find Narayanan. They squabble and argue a lot, but soon Ajay falls in love with Anjali. However he does not tell her of his feelings. After taking her on a trip to his hometown, he realizes that she does not reciprocate his feelings. Soon, Ajay tracks down Narayanan (in a chance encounter earlier, Ajay pockets Narayanan's address from his wallet) and blames him for the misery in his life, because it was Narayanan's trickery that brought them together and now Ajay cannot live without her love. Narayanan decides to help Ajay and he visits the house under the pretense of being Ajay's friend "Billa". He tries to make Anjali fall for Ajay. Anjali's fiance Deepak (Rahul Ravindran) then gives Anjali a surprise visit, just as she begins to like Ajay more and more. Narayanan continues to try to bring Ajay and Anjali together to no avail.
On the night of her birthday, Ajay decides that Anjali will never love him, and resorts to drinking, depressed. Meanwhile, Anjali realises that she loves Ajay, but is angry at him for his behaviour under the influence of alcohol. The next day, she goes to the wedding of Ajay's colleague as his wife (his colleagues think she is his wife) and looks for him there. Just when they find each other and are about to confess their feelings for one another, due to a misunderstanding, Anjali thinks that Ajay and Narayanan are tricksters and have planned the whole same-house plot. Enraged, she returns to London.
Three months later, as Anjali wins her photography contest, Deepak tells her that Narayanan had told him everything from scratch, and convinces her that she loves Ajay and vice versa. Anjali comes back to their flat, and looks for Ajay, but to no avail. Just then Ajay opens the door and finds his passport that he was looking for. Anjali meets him at last and is thrilled. She asks him why he did not come to fetch her for three months. Ajay tells her that he got his passport only then and had been going to the airport. As the two reconcile, Narayanan enters with a prospective victim (Udhayanidhi Stalin) to trick and shows him the house. Thus the film ends with the same trick that brought the two together.