The long-lost buddy of wildlife photographer Venkat Ramakrishnan, Panchavan "Pari" Pariventhan, is said to be somewhere, according to a call from Srivatsan, an old college classmate of Venkat's. When Srivatsan informs Venkat and his other friend Sevarkodi Senthil that Pari is in Ooty, they dash to meet him. They started searching for him. In a flashback, Venkat's father makes him study engineering. He makes friends with Pari, a carefree student who is enthusiastic about learning, and Senthil, whose family depends on him to help them overcome poverty. Virumandi Santhanam, also known as Virus, is the harsh and callous principal of their college.Engineering major Paneerselvam is not allowed to graduate from Virus since he missed a project deadline. Paneer tells Virus that he had been putting off turning in his project so that he could take care of his father's medical needs. After Pari and his friends finish his project, they discover that he has taken his own life. Pari approaches Virus to alter his opinions on academic pressure and suicide, but he rejects her. The families of Venkat and Senthil receive letters from virus criticizing their subpar work. For lunch, the three show up at Virus's daughter's wedding, where they meet Virus's other daughter, Riya.Virus alerts Senthil and Venkat to Pari's negative impact. Senthil moves in with Srivatsan, an advocate of memorization. After Pari and Venkat humiliate Srivatsan in public, Pari and Srivatsan place a wager on each other's future success. Pari gets Riya to end her engagement to her fiancé. Senthil and Pari make amends when Pari saves Senthil's father from a heart attack. Riya grows fond of Pari. Pari receives the highest score among the buddies when their examinations are over.When Venkat, Senthil, and Srivatsan arrive at Ooty in the present, they meet a man posing as Pari. This person discloses that the real Pari is actually Pappu, the gardener's son from the Pariventhan family, who took on the name of Pari while the real Pari was studying overseas. They go to Dhanushkodi after learning that Pappu is there. Pari and Riya start dating in their senior year of college. Following a break-in at Virus's residence, Virus threatens to kick Senthil out if he doesn't testify against Pari. Senthil makes an attempt at suicide because he doesn't want to let his family or Pari down, but his friends stop him. Virus retracts his promise to fire Senthil, and Senthil gets employment. Venkat persuades his dad to support his desire to take wildlife photos.Venkat and Senthil take Riya from her wedding to Pari in the present. Virus kicks the three out of his last year when they steal an exam paper, but he subsequently lets them back in when they assist him in delivering his grandson during a storm. The day of graduation, Pari vanishes. Venkat, Senthil, Riya, and Srivatsan meet up with Pari again in Dhanushkodi; Pari is now revealed to be Kosaksi Pasapugazh, a prosperous businesswoman. Srivatsan concedes the point.