Synopsis; He will kill you with laughter till you cry for mercy. In the early 70's - Bombay was taken over by smugglers and gangsters. One of them was Don Muthuswami. On his deathbed Don Muthuswami's father extracts a promise from his son that he would go straight. Muthu decides to invest in a legitimate company. He engages an Urdu/Hindi teacher Jaikishan to improve his language. He thus starts his journey to change from Don Muthuswami to Sir Muthuswami. Now the only issue left is to get his daughter Sanjana married and the best match according to him was his very good friend Don Vardhan's son Pradhan. Sanjana however would marry anyone but Pradhan. Preetam, Muthu's general manager comes to Muthu and asks for his daughters' hand in marriage. Muthu says his daughter deserves a man who earns millions. Preetam claims to be a millionaire and reveals that he became a millionaire by stealing from Muthu. In the meanwhile Muthu's daughter is desperately thinking of a way so that she does not have to marry her father's choice. She calls him and tells him that she is pregnant. Muthu is shocked and concludes that Preetam has made his daughter pregnant. A cute girl, Ranjana comes to meet Muthu and tells him that she loves his manager Preetam and admits to Muthu that she had lied to Preetam about being Muthu's daughter. Muthu is relieved that Preetam is not Sanjana's boyfriend but now wonders who could be the father of her baby. How does Muthu get back the loot from Preetam? Who is the father of Sanjana's baby? Who marries whom? Who Is Ranjana? What happens to the opposition gangsters? How does Don Muthuswami handle the police? If you want to know all this - you have to watch "Don Muthuswami"