A lorry drives down the highway, knocking down a police motorcycle and destroying a police vehicle. A police officer informs the DCP, who successfully stops the truck by pointing a gun at his head. He forces the driver to open the back, which he does. The driver opens the door to reveal 300 crores in the lorry. The driver asks to split the money, to which Tamizhselvan hits him. The next day, Tamizhselvan reports to the media that 50 crores was recovered and handed to the
government, and the driver got arrested. Arjun Ramakrishnan comes to
Chennai to woo a psychology student named Divya, whom he has a
crush on. With the help of a local, incompetent don named Deva, he successfully wins her heart. Divya's elder brother is Tamizhselvan, an honest and sincere
DCP in Chennai. He approves of the relationship between Arjun and his sister, and soon their wedding is fixed. One day, some goons kidnapped Tamizhselvan in retaliation for his thwarting a
black money scam six months ago. Arjun rescues Tamizhselvan and takes him home, only to reveal that he is really a
CBI officer who discovered 250 crores stashed in Tamizhselvan's house as black money. During the black money raid from a lorry, they seized 300 crores, but Thamizhselvan publicly announced that they seized only 50 crores. Arjun takes away all the money but does not arrest Tamizhselvan due to his public reputation instead of telling him to surrender personally. The driver gets released from jail and goes to Tamizhselvan's house. However, Tamizhselvan soon discovers from the driver that Arjun is not a CBI agent but a recent prisoner who just got out. He pursues Arjun, intending to get back the money. During the chase, he opens fire on Arjun's
SUV, causing Arjun to lose control and meet with an accident, losing consciousness. Arjun wakes up in a hospital, having lost his memory. Tamizhselvan keeps Arjun in custody in a house where a psychiatrist named Dr Boothri is assigned to restore Arjun's memory so that he can reveal where he hid the money. Unknown to anyone, Arjun had not lost his memory. He is only pretending as part of his mission to retrieve black money. At night, he sneaks out of the house and steals the black money of a
Union Minister, converting it to white with the help of a
hawala trader. However, Tamizhselvan and the Union Minister soon learned that Arjun did not lose his memory and stole even more black money. Arjun, confronted by Tamizhselvan and the Union Minister, reveals his motive for stealing the black money. In the past, Arjun is from Manimangalam. It is an isolated village lacking basic amenities like roads, water, high schools, and proper housing and sanitation facilities. When the building of the only primary school in the town collapsed, Arjun confronted the local
MLA, Sivagnanam, who presented a false account of the development of the village by pocketing all the money meant for developing Manimangalam village. Sivagnanam rudely sent him away, defending his corruption and declaring that he would never improve the town. Following this, Arjun approached the Union Minister, who also turned out to be corrupt like Sivagnanam. Arjun's friends confront Sivagnanam and his men, who kill two of them and kill Sivagnanam. Arjun later decided to get back all the black money acquired by Sivagnanam (which was the ₹300 crores recovered earlier) and the Union Minister and use it to develop Manimangalam. In the present, Arjun takes Tamizhselvan, the Union Minister, and Divya to Manimangalam, a well-developed village. He reveals that he had used the money hoarded by the Union Minister along with Sivagnanam's ₹300 crores to develop the town and gave credit to the Union Minister, because of which the villagers now hold the Union Minister in high regard. Tamizhselvan drops all charges against Arjun, seeing that he had stolen the money, which was black for good intentions, and arrests the Union Minister. The credits revealed that Divya, Tamizhselvan, and Arjun are all actively involved in Manimangalam's development. ==Cast==