Sundara Boopathy is a rich landlord who is widely respected by everyone in the town. Following the death of his first wife, he remarries Alangaram. Kannan is Boopathy’s eldest son, born to his first wife. Viswam is Kannan’s half-brother. While Kannan is a good and kind hearted person taking care of all the family businesses, Viswam is a spoiled brat who just roams around spending unnecessarily. Viswam also has a hatred towards Kannan. Radha is the cousin of Kannan. Kannan and Radha are in love and the family plans to get them married. Boopathy keeps worrying about Viswam due to his irresponsible behavior and requests Kannan to shape him into a good human. Boopathy falls ill and is on his death bed. At that time, he calls Kannan and tells him a secret after which Boopathy passes away. Kannan assumes all responsibilities of running the businesses and this angers Viswam. As Kannan does not know swimming, Viswam decides to murder Kannan by pushing him into a river. Viswam takes Kannan with him in a boat and pushes him in the middle of the river and stages a drama that their boat had an accident in which Kannan was dead. The entire family is shocked hearing about the demise of Kannan. Viswam feels happy as he has got a free hand in spending the wealth. Kannan Home Car Driver Sabapathy watches a stage play where he witnesses Kannan’s lookalike Chinnaiya. Sabapathy is shocked and devises a plan to make him act as Kannan, so that the family members could feel relieved. Sabapathy meets Chinnaiya and requests him to act as Kannan. Although Chinnaiya is not interested, he agrees to be a part of the plan. Sabapathy provides all the necessary info for Chinnaiya about Kannan’s family members. Chinnaiya goes to Kannan’s house and says that he is not dead. Everyone in the house feels happy except Viswam who feels suspicious about the new Kannan. Viswam tells his family members that the new person should be someone else acting in place of Kannan to steal money. But Chinnaiya clears the doubts by performing certain tasks which Kannan does on a regular basis. Chinnaiya tries hard to make Viswam a good person, but in vain. Finally, the house members overhear Sabapathy’s conversation and find out the plan. Sabapathy accepts the truth. To everyone’s surprise, Chinnaiya says that he is none other than the real Kannan. He tells a flashback, where Kannan was rescued by a group of stage actors who were travelling in another boat. Kannan asked his friend to bring Sabapathy for the stage show, so that Sabapathy could see Kannan in the name of Chinnaiya. Kannan preferred to hide his true identity as he does not want Viswam to be framed for murder. Viswam tries hard to make everyone believe that he is not Kannan. To prove his identity, Kannan discloses about the secret told by his father Boopathy before death. Boopathy told Kannan about the location of jewels that belonged to his mother which was secretly hidden in a place. Kannan says this to everyone and promises that he will bring those jewels back so that he could prove his identity. Viswam follows Kannan and tries to kill him. In the fight, Viswam slips down in a well but is saved by Kannan which transforms Viswam. In the end, Kannan’s identity is proved and he is also married to Radha. Viswam is transformed in to a good human and Kannan feels happy that he has fulfilled his promise to his father.
The Success of A. C. Tirulokchandar Direction Movie's Thangai Starring Sivaji Ganesan Prompted further Cominations in the same genre between the pair with Iru Malargal and En Thambi being released soon ofter.
