Rangan (M.G.R) the very loving brother of Thangam, though only a cart puller, dreams of educating his sister, to become a doctor. So, when he learns of his sister's love with Murali (Muthuraman), a doctor, he gets them married, in a grand manner. Murali's mother, after their marriage, learns that Thangam is the daughter of Velappan, her husband's (mill owner Karunakaran) murderer. Thangam is thrown out of the house. Rangan finds out that his father, who is still languishing in jail, had been falsely implicated. He vows to bring the real culprits to book. His fiancé Valli (Jayalalitha), helps him nab the murderers. It is proved at last that justice always wins.
A woman gets ready to leave for a get together and finds her husband dead in their room. In no time, she is also tried to kill by a black masked face man. His attempt gets failed and he escapes. The woman is now in state of shock and mentally paralysed. A murder case is registered and investigation take place. Susi (Kanchana) a young college girl comes to her home for vacation along with her friends. She lives with younger paternal uncles Kamalanathan and Vimalanathan who are the younger brothers of the victim and her aunt who was supposed to be the victim in the hands of the murderer. Susi meets Baskar (Ravichandran), a singer and both of them are attracted to each other at first sight.