Can true love change the heart of even a hardened criminal? This is the question thrown at the audience in 'Vidiyumvarai Kaathiru'. Raja (Bhagyaraj) is a hardened criminal, forever plotting to usurp the property of others. He comes to Ooty and wins the confidence of Rajshekar, a rich businessman. Rajshekar develops so much faith in Raja that he gets him married to his own mentally unstable daughter Satya (Satyakala) and bequeaths all his property in her name. He also adds a clause that in case Satya meets with her death, then all the property would go to Raja. Raja plots and makes several attempts to kill Satya, but always fails. At last, he comes to know that all along, Satya has been aware of his plans. She now begs him to surrender to the police as she is in the family way. Does Raja have a change of heart? Does he surrender or does he kill her and run away with her property?