Don Muthu Swami is Mumbai's notorious smuggler and gangster. On his deathbed, Don Muthu Swami's father makes his son promise to leave the underworld and live a straight life. Muthu decides to invest in a legitimate company and starts his journey to change from Don Muthu Swami to Sir Muthu Swami. He wants his daughter Sanjana to marry Pradhan, his friend's son.
While Preetam, Muthu's general manager comes to Muthu and asks for his daughters' hand in marriage. To impress Muthu, he claims to be very rich by stealing millions from Muthu himself. Shock awaits Muthu as Sanjana tells him that she is pregnant. Muthu concludes that Preetam is behind his daughter's pregnancy. While a girl named Ranjana claims to be Muthu's daughter and tells him that she loves his manager Preetam.
Who is the father of Sanjana's baby? How does Muthu get back the loot from Preetam? Who Is Ranjana? How will Don Muthu Swami handle the police and the opposition gangsters?