Shiva Raman, an easy-going young man from Chennai, comes to London (UK) in search of a job, but loses all of his certificates. He finds Kathiravan wandering in London aimlessly without a job. Now, they both need job and money. Kathir persuades Shiva to join a bank robbery planned by Bhaskharan. His stammering brother Natrajan and Aishwarya, who is Bhaskaran's lover, are in on the job. Aishwarya informs the police about the robbery and tells that the entire plan was hatched by Bhaskaran. Bhaskaran hides the money before getting arrested, and the place is known only to his lawyer Vedimuthu. Aishwarya pretends to be in love with Vedimuthu to find where the money is hidden.

Meanwhile, to find a safe cover, Shiva and Kathir plan to imitate Saravanan, the grandson of a rich elderly couple: Rajasekar and his wife Parvathi. They have not seen their grandchild since his birth. Shiva and Kathir end up feigning to be Kadhir's body and Shiva's voice to make up for Saravanan in front of the blind couple. Ganesh, who knows Kathir before, makes several attempts to expose the truth to the couple, but all fail, due to Shiva and Kadhir's luck. All of a sudden, Anjali arrives pretending to be Saravanan's lover. She calls on all the relatives of Rajasekar and Parvathi. The relatives arrive in Shiva's absence. Finding no way out, Kathir pretends to have fainted, and he is admitted to the hospital. Shiva comes to his rescue, and says that he is Dr. Karthikeyan, a friend of Saravanan from America.

Amidst their drama, Kathir tries to steal the Lord Muruga statue, for which he plays a trick to injure Parvathi, which keeps all others out of the house for sometime. Shiva engages in a fight with Kathir when he tries to leave with the statue that he had stolen. Rajasekar accuses his relatives for his wife's accident and asks all of his relatives to leave at once. Shiva and Kathir get separated and part ways. A drunk Ganesh finally manages to reveal the truth to Rajasekar about Saravan's death in an accident following which Anjali reveals the truth to him that she is actually Saravanan's secretary and had come to explain about Saravanan's death in an accident in America. She also explains that Siva and Kathir were acting/posing as Saravanan & that she took part in the drama not wanting to ruin their happiness. After revealing all this, she gives them money and asks them to get out of the house. Shiva, realizing his mistake, refuses to take the money and asks Kathir not to take the money. Kathir leaves Shiva in anger, taking the money with him. Shiva returns to Rajasekar and confesses all of his mistakes. Rajasekar asks them to continue the drama for the sake of his wife, who loves her grandson more than her life. Parvathy comes and calls Saravanan but gets no replies. She finally gets hold of the arms of Kathir, who has returned in remorse. Hence, the movie happily ends with the marriage of Shiva and Anjali, who by now have fallen in love with each other.