Vijay Antony, Siddharth, Venugopal, Rupa Manjari
Karthik (Vijay Antony) is a brilliant student. The school head master catches him once for forging the signature of his friend's parent in the mark sheet. The head master sends for his father. He goes back to his house and knocks the door, but there is no response. So he peeps through the window and is shocked to find his mom with another guy of the village. His mother opens the door and pleads him not to tell his father, But he does and so his father commits suicide.
Karthik's mother continues her relationship which leads Karthik to kill his mother and the guy by setting the house in fire. He is sent to juvenile home where he grows up. On release, the jail warden gives him the address of his uncle (father's younger brother) and asks him to concentrate on his studies. He goes to this address and realises that his uncle's wife is not interested in giving shelter to Karthik. So he leaves takes a bus to Chennai to start a new life.
As fate would have it, the bus meets with an accident and his co-passenger Saleem dies.
Karthik picks up his certificates and joins a medical college by changing his identity as Saleem. He develops friendship with a rich guy in his college, named Ashok (Siddharth Venugopal) and also with his girlfriend Rupa (Rupa Manjari) who are befriended with a guy named Suresh[Vijay Victor].Ashok allows Karthik to stay in his house,suggested by Rupa so that Karthik need not have to shell out his hard-earned part time money for his rent.One day in a while the jail warden(in his juveline home), recognizes him when he was with Ashok, as Karthik,but Karthik having impersonated himself as Salim,discards him and picks up a quarrel with him that he is not Karthik.This creates a dilemma in the mind of Ashok of his identity.One day,Ashok and Suresh plan to to go for an excursion to a farm house,where Rupa denies to come. Suresh suggests him to take some other girls instead,to have a ball there with some female companions, thereby discarding Karthik to the trip. Rupa though she loves Ashok,suspects his fidelity as she came to know through Karthik that he went to farm house with other girls.When this is known to Ashok,he gets enraged.Thinking that Karthik has betrayed him to Rupa,he slaps him and asks him to vacate his place.Karthik,seeing no other way apologizes to him and looks for another lodging.But Ashok doubts his identity,triggered by the quarrel at that time with that jail warden and decides to confirm of that. He opens the briefcase of Karthik while he was at shower.He finds a photograph and realizes that the father was different from the one he had introduced to Ashok earlier. He confirms that Karthik is not Saleem.
Suddenly Karthik enters the room and asks Ashok to give back the photo.But Ashok refuses and removes the towel that Karthik was wearing and confirms that he is not a Muslim as it was not Circumcisied. Karthik gets angry and pushes Ashok in a rage which ultimately kills him. At first, he is shocked by this unexpected accident but later covers up the murder so intelligently,no one ever found out that Ashok is dead .Now Karthik impersonates himself as Ashok,when a family friend of Ashok's father(who has seen Ashok only in his childhood),plan to meet him and mimics(as he is good at it)as Ashok, to Ashok's parents and Rupa,running the show as if Ashok is still alive. He is able to cover it up,till Suresh finds this out. Karthik kills Suresh. The next day the police comes and say that they have found Suresh's corpse.
They interrogate everyone from the college professor to Ashok's family friend's daughter Priya(who was befriending Karthik impersonated as Ashok for a short while) including Karthik but could never find out the truth.They presumed that Ashok has killed Suresh in a quarrel and is absconding and conclude that Karthik is innocent and a studious person.Karthik continues to live as Saleem after seeking permission from Saleem's dad and promises to take care of him.