Sivaji, an Indian software architect, returns to India from the United States. He aims to establish a non-profit trust called Sivaji Foundation, which includes a network of hospitals and educational institutions that serve the poor free of charge. An influential businessman, Adiseshan, sees Sivaji as his competitor because he runs profit-making educational institutions and hospitals. Sivaji is forced to bribe the corrupt civil service, but eventually, the bribes demanded become so high that he has to mortgage his house and sell his car to pay them. When Sivaji goes to court, he loses the case filed against him by Adiseshan regarding the methods Sivaji had used to open his foundation as a result of bribing numerous government officials. Simultaneously, Sivaji falls in love with a girl named Tamizhselvi. However, upon asking for his horoscope, an astrologer warns that their union will result in Sivaji's death. When Tamizhselvi refuses the proposal due to her concern for Sivaji, he calms her fears and convinces her to marry him.
Following the loss in the court case, Tamizhselvi requests Sivaji out of fear not to come for her again. Sivaji is reduced to utter poverty. Realising that the methods he used are unlikely to work again, he decides to play the game his own way. Sivaji, with the help of his uncle Arivu, acquires evidence of ₹2 billion worth of illegal earnings in Adiseshan's possession and uses the documents to blackmail Adiseshan into giving him half the money. He further obtains details on people who have illegal earnings across Tamil Nadu and blackmails them to give him half of their illegal wealth. He then transfers the money to the bank accounts of his friends around the world by hawala forgery. They then deposit the money as donations to Sivaji Foundation, making the money usable and legitimate.
Sivaji informs the Income Tax Investigation and Vigilance Department about the details of the illegal money held by the tax evaders (including Adiseshan) and gets them arrested. He reopens the foundation and soon is able to provide free, good quality education, infrastructure, services and employment to people in every district of Tamil Nadu. Led by Adiseshan, those who were blackmailed by Sivaji exploit Tamizhselvi's innocence to silence him. Fearing for Sivaji's life, she hands over Sivaji's laptop to the CBI and Income Tax officers hired by Adiseshan with all the information regarding the illegal money transactions. With presentable evidence, Sivaji is arrested.
Adiseshan and the police order Sivaji to unlock his laptop. When Sivaji refuses, Adiseshan tortures him, leaving him for dead. To cover this up, Adiseshan and the police organise for thugs to shoot at the police van that will carry Sivaji's body, making it look like a murder by a third party. Sivaji, however, is faking; he was informed of the plans to kill him by a sympathetic police constable prior to the interrogation. Left alone in the room, he electrifies himself. Sivaji's friend Dr. Chezhian, Tamizhselvi and Arivu intercept the police van after being informed by Sivaji through a MMS and replace Sivaji's body with a dummy before the thugs open fire. While everyone thinks that Sivaji is dead, Chezhian revives him using a defibrillator. Following Sivaji's "death", Adiseshan and the CBI still try to open Sivaji's laptop by trying to fool the voice-detection program; they fail and all the data in the laptop is erased. ReadMore>