Arivazhagan aka Arivu hails from Kolaikkara Kuppam a.k.a. Cooliekkara Kuppam, a slum area in Chennai. He is one such responsible youth who focuses on working for the betterment of his fellow beings, and he works hard for the same. Arivu starts Kuppam FM 90.8, a local radio channel with the help of the area gangster, Kasi. In reality, Arivu tries to free the people of the area from the atrocities of Kasi, who is deliberately preventing them from becoming independent, so that he may continue to dominate the area.[6]

Arivu succeeds in turning the people of the area against Kasi, thus destroying his support. Later, Arivu joins a leading FMCG company called Saffron and joins its sales department under Stella Bruce. He manages to bring his friend Bhagya out of Kasi's gang and gets him a job in Saffron. He meets Aadhi, Saffron's brand manager, who teaches him how to progress by doing smart work, and Arivu considers him as his inspiration.

On the night of 1 April, Kasi and his gang attack and stab Bhagya in Saffron's warehouse, whereupon he dies in Arivu's hands. Arivu, filled with rage, tries to attack Kasi, but Kasi's rival Doss attacks and stabs Kasi in retaliation for their previous encounter. Arivu admonishes Kasi for being a paid henchman. Kasi reveals to Arivu that he killed Bhagya on a contract given by Jayaram, the President of Saffron. The motive was that Bhagya tried to help Kasthuri, who filed a case claiming Saffron's products to be adulterated, due to which she lost her son.

Arivu is addressed by Kasi as being a worse hitman than he himself is. Arivu then saves Kasi, who tells Arivu that all products manufactured by Saffron are adulterated. Arivu takes up a mission to fight such malpractices not only in Saffron, but in all the other five major food companies, including the one owned by Madhav Kurup. Arivu shares all of his plans with Aadhi. Meanwhile, is revealed that Aadhi is actually Adhiban Madhav, Madhav's son. He joined Saffron to know their trade secrets and merge the company with his father's company.

Arivu manages to convince his company's staff to manufacture products as per government regulations for two days. At the same time, he convinces the staff of the other companies to wear a kerchief on their dresses for the next two days, thus tricking the owners into believing that their workers have turned against them. However, Aadhi manages to foil Arivu's plan and coerces the other owners to write over the major shares of their company to Madhav, thus making him the deciding authority of all their companies.

Aadhi manages to turn the employees against Arivu by tricking them into believing that Arivu worked as a spy for Madhav. Stella Bruce then slaps and humiliates Arivu, while Aadhi pretends to defend Arivu, claiming that he is innocent and that it is the new president who conspired all these. After this, Arivu reveals to Aadhi that Stella Bruce was his ally, and he now knows that Aadhi is the true traitor. Aadhi then burns down the godown containing the unadulterated products and reveals to Arivu that he is Madhav's son and will be the next CEO of the company.

Aadhi also convinces the staff through his clever tactics and makes them propose his name as the new CEO, also revealing to Arivu that he will make them manufacture adulterated products without their knowledge, now that he commands their loyalty, support, and trust. Arivu goes to the Radio Mirchi radio station on the night before 1 May. He reveals that after the fire, one of the injured department heads of Saffron, Karpaga Vinayagam, called him into the ambulance and told him that he followed the regulations on the third day too.

Arivu learned from the other Saffron team workers - Kennedy, Vinoth, Ansari, and Sivaranjani - that after manufacturing quality products for two days, they could not bring themselves to manufacture adulterated products on the next day. They confirm they all followed government regulations, thus manufacturing quality products on the next day. Aadhi, now the CEO, hears the workers say that they will rebel against him and depose him if he tries to revert to manufacturing adulterated products.

Arivu adds that the loyalty of all the employees in every field should not be wasted by showing it towards unethical employers. Aadhi then vents his frustration about the failure of his plan. All the people in the city show their support to Arivu, who celebrates his success with his love interest Mrinalini, friends, family, the people of his slum, and the people of the city as the film ends.