The story starts off with Raghu, a passport-issuing officer, and his wife Shanthi, who live in Chennai. Raghu, being an honest man, tells Shanthi that he cheated on her with a coworker when he was in Goa. She immediately leaves for her mother's house. Raghu, being a transformed gentleman, tries to stop her by apologizing, but in vain. Raghu's brother Vijay, being a good and supportive brother, and Shanthi's brother Suriya, being a non-emotive but supporting brother, meet in a cinema theater. Vijay blames Shanthi to be the cause of the problem, and Suriya blames Raghu for the same. They keep on fighting at every chance. Meanwhile, both Vijay and Suriya find their own lovers in Akhila and Asha respectively and fall in love.

One day, Raghu finds a bundle of cash on his table and meets Muthukumaraswamy, the person who kept the money there. Raghu finds out that Muthukumaraswamy is a businessman who is wanted by the police for the crime of forex fraud. Muthukumaraswamy wants to leave the country to escape from the police, and he needs a fake passport to flee the country; otherwise, the police will catch him. Since his passport is confiscated by the police, he tells Raghu to get one for him, but Raghu, being a sincere officer, disagrees and calls the police instead. Muthukumaraswamy gets angry and promises to avenge Raghu. Meanwhile, Raghu and Shanthi apply for a divorce according to the Hindu Law of Divorce. Child custody of their daughter Sona, who was in Shanthi's sister's house when the breakup occurred, is given to the mother by the court. One day, Suriya takes Sona to a festival fair and somehow loses her. In the confusion that follows, Sona falls from a Ferris wheel and is taken to the hospital by Vijay. She is brought to Raghu's house once she recovers. Soon, Vijay discovers that Sona has lost her hearing in the accident. Some days later, Suriya finds that Sona is missing. Suriya finds Vijay, and the two get into a huge fight. Then, Raghu tells everyone that Sona is in his sister's house. Since Sona's custody is given to the mother, this action of Raghu's is wrong in the eyes of the law.

Shanthi and Suriya, accompanied by a lawyer, come to Raghu's house to get Sona back. At that time, Raghu suffers a serious asthma attack while in the bathroom, and everyone saves him. After recovering, Raghu tells everyone that Sona is not in his sister's house but has been kidnapped by Muthukumaraswamy, who is out on bail. In a turn of events, Raghu issues a fake passport to Muthukumaraswamy, but Raghu does not want him to escape from the police. The two heroes join hands to make sure that this does not happen. Sona is with Muthukumaraswamy's wife and brother-in-law Kachiram in a van. Vijay and Suriya both search for Sona, then find out that she is in a van. Sona, after seeing both Vijay and Suriya on a bike, throws her family photo from the van. Meanwhile, the van reaches the safe place, and Kachiram calls Muthukumaraswamy to share the news of their arrival. They both decide to insert a bomb in Sona's hearing device. Muthukumaraswamy's wife then decides to save the child. Her brother Kachiram fights her and puts her in the van and activates the bomb which will explode in 10 mins. Then, Vijay and Suriya catch the van, and a fight between Kachiram and Vijay ensues. Meanwhile, Suriya takes Sona home along with her hearing device which still has the bomb. In the middle of the fight, Kachiram drives away in a car. Muthukumaraswamy's wife shouts to Vijay to save Sona by telling him about the bomb. At the airport, Kanthaswamy, the Chennai Deputy Commissioner of Police, arrests Muthukumaraswamy. As Suriya reaches home, Vijay follows them. Once Vijay reaches home, he throws away Sona's hearing device before the bomb goes off. The film ends Vijay and Suriya becoming best friends again after a long time and reconciling with their lady loves, and Raghu and Shanthi also embrace each other with Sona.