A group of four youngsters get on a train. They are then scolded by a quick-tempered stranger named AK (Prakash Raj). He tells the friends that today's young people are immature and good-for-nothing. The friends are about to prove him wrong. Nandhini Velu Nachiyar (Srushti Dange), Reshmi Kaur (Amrita Chhabria), Mahesh Muthusamy (Nadhim Khan), Mohammed Aslam (Roshan Nawaz), and Angelina Kristy (Nakshatra) were visual communication students and best friends. After the graduation, they had to split up and to go in different directions. Then they met the magician Thyagu (Krishnakumar Balasubramanian), and everything changed. Thyagu and Nandhini were childhood friends and were in love with each other. However, both were from different castes. Nandhini's brother-in-law Raja Rajasekharan (Vijay Gopal) was a despicable caste fanatic and an influential person. He had hatred towards every caste other than his and wanted his community people to get a high post in the society. Thereafter, the six friends formed a group named "Mantra", performing dance, magic, or songs for advertisement companies. When Raja was made aware of Nandhini's love, he killed her and swept this issue under the rug. The five friends protested to grant justice for Nandhini's death, but the police force stopped the protest and beat up the friends. The five then started a TV show in which they exposed the truth behind Nandhini's death. When the four friends reach their destination, AK is shocked to see Thyagu and Nandhini together. He later reveals that he is actually a CBI officer who was in charge of Raja's case and then forces the friends to tell him what happened. The friends reveal that Nandhini's death was a sham and they used a fake body to make it look like Nandhini. Also, Raja committed suicide when the police tried to arrest him for a murder he did not commit. While AK is initially unhappy at first, he praises the youngsters for their braveness and hushes up the case, revealing his real name as Ananthakrishnan. He then departs as the six friends rejoice in happiness.