Two music directors Bharathi (Vijayakumar) and Kannan (Nassar) used to be friends and composed music together. After Kannan has a fight with the director of their movie, Bharathi who feels embarrassed decided to split from Kannan and compose the music for the film by himself. He offers Kannan the chance to reconcile after this movie. Kannan rejects this and instead gives details about the fallout to the newspaper and Bharathi ends up losing the movie deal. A war begins and both music directors hate each other and can’t even stand to hear the other’s name. Bharathi is very successful while Kannan, who is basically unknown, drinks away his sorrows.
Kannan’s daughter Janaki (Jyothika) lives with her grandparents and mother in Bangalore while her father Kannan is still struggling with his friend Ramanathan (Delhi Ganesh) in Chennai. Janaki goes on a college tour and stays at a hotel. Coincidentally it is the same place where Krishna (Suriya) is staying. He falls in love with her and tries to woo her. However she ignores him and even pretends to be deaf and mute when he invites her to spend time together. At the end four days, Janaki’s tour is over and her bus leaves for her college but leaves her behind as she is late. She ends up catching a public bus home. Krishna sees her gets on the bus and tries to impress her. Even though she is attracted to him slightly, she is annoyed and ends up getting of the bus and getting a lift from a drunk guy who can’t control his car. He stops the car and tells her to drive. Krishna comes and agrees to drive the car and they put the drunk guy in the back seat.
They bond on their journey and Janaki tells Krishna that’s she starving. Krishna convinces a shop owner to reopen his shop by telling him that Janaki is his wife and that she is pregnant. They soon realise that the drunk guy became sober and drives away, leaving them stranded. Janaki pretends to be heavily pregnant by stuffing Krishna’s jumper under her clothes and manages to stop another bus. On their journey they learn who the other’s father is and are shocked. Krishna takes Janaki back to her college and leaves. Janaki follows him and they admit their feeling for one another and get together. Krishna now has to return to Chennai as his mother (Ambika) breaks her leg and is in hospital. He promises Janaki that he will speak to his father about their marriage. Janaki has one condition: She says that if they disapprove she will not elope with Krishna without her parents’ consent. Krishna agrees and goes to see his mother.
The doctor (Kovai Sarala), who has really bad memory provides comic relief along with her assistant (Maadhu Balaji), tells Krishna’s mother that she will send a nurse to their home to help her. While this is happening Bharathi has a fallout with a prominent music director (Karan) and Kannan is recruited to anger Bharathi. Kannan’s music in the movie becomes extremely successful and he becomes an overnight sensation — gaining fame and being flooded with offers. Bharathi is severely affected by the fallout and loses his prominence and offers. This further angers Bharathi and his hate for Kannan only increases. Seeing this, Krishna tells Janaki that they must separate before he comes with a new idea. He will somehow make Kannan like him and Janaki will make Bharathi like her. As per the plan, Krishna goes to Kannan’s house as a driver while telling his parents that he went to Bombay to pursue further studies; Janaki pretends to be the nurse that the family doctor sent and tells her parents that she has an extra class at college.
Krishna assumes the name of Driver Pandi while Janaki assumes the name of Nurse Kalyani. It is not all that smooth as the doctor who is known to both families sees both of them at each other’s houses and becomes very confused, providing further comic relief. Due to her severe bad memory, they are able to persuade everyone that she is just confused. The doctor gets extremely confused and believes that they are all separate people that just look alike. Janaki impresses Bharathi and his wife while Krishna does the same at Kannan’s house. Problems arise when Krishna is kicked out of Kannan’s house when he takes the blame after Kannan’s father-in-law accidentally blabs to the media about Kannan’s drinking. Janaki is kicked out as she stands up to Bharathi and tells him it is ironic that he is named after Bharathiyaar who fought for women’s rights while he doesn’t allow his wife who is a singer to sing in public after their marriage.
Bharathi soon after realises his mistake and invites Janaki back. Krishna, however, has to struggle much more to gain back Kannan’s trust. Kannan, after a drunken fight with the famous director who introduced him, angers the director — he refuses to see Kannan leading to a bad image of Kannan in the media. Krishna follows the director day and night and even stays in the rain all night. When allowed to speak to the director, he convinces him to forgive Kannan. When Kannan realised that Krishna helped him out despite his anger he invites him back to his house. Krishna and Janaki tell Kannan and Bharathi respectively that they are in love and that their parents and their lover’s parents are against it. They convince them to speak to the parents of their lovers. The families arrive at a beach house and are shocked when they find out who Krishna and Janaki really are and that they have been fooled. Kannan storms off. Bharathi accepts the reunion and so does Kannan’s wife who tells them to arrange the wedding and that Kannan will come as he wouldn’t miss his only daughter’s wedding.
Kannan does not turn up. Janaki and Krishna turn up at his house, and he is devastated that they got married without his consent and feels that no one respects him. Krishna tells him that they are not married and that they won’t until he approves. Krishna claims that they will wait and remain lovers until Kannan gives his consent. As Krishna drives away he comes to a sudden halt as Kannan and his family have also arrived by car and blocked his path. Kannan tells him that all fathers will object, but he didn’t expect Krishna to do what he did. He tells him that he better marry Janaki or else. Janaki then brings Bharathi while Krishna brings Kannan to him, and the old friends reunite in an embrace. In the final scene the doctor arrives and informs Bharathi and Kannan that Driver Pandi is actually Krishna and that Nurse Kalyani is actually Janaki to which the men act surprised before they inform her that they already know.