The movie starts with Sugan (Karthi) and his friend Parasuram (Premji) being chased by cops. The flashback shows Sugan as a womanizer who has a weakness for Biryani, and Parasuram, who is his childhood friend. Sugan's womaniser attitude always gets him into a fight with his girlfriend Priyanka (Hansika Motwani). Sugan and Parasuram attend a function for a branch opening of one of their offices, where they meet Varadharajan (Nassar), who is the chief guest for the ceremony. In the meantime, it is shown that a CBI officer named Riyaz Ahmed (Sampath Raj) has been deputed to track Vardharajan's illegal activities. Varadharajan gets impressed with Sugan and later decides to make him his son-in-law, and this decision gets him into an argument with his elder son-in-law Vijaykrishna (Ramki).

Varadharajan later hosts a cocktail party and also invites Sugan and Parasuram, where they get drunk. Sugan, who craves biriyani after getting drunk, searches for a biriyani shop. There, they both come across Maya (Mandy Takhar), a prostitute. The very next day, they find police cars searching for Varadharajan, who is missing. Meanwhile, Sugan and Parasuram find Varadharajan's corpse in their car trunk. They are blamed for Varadharajan's death and are chased by police, which is the starting scene of the movie.

Sugan and Parasu go to their friend's house, and Parasu sends a picture of Maya to his friends. The next day, one of their friends finds Maya at Egmore Railway Station. Sugan comes there, and Maya confesses that she spiked their drinks upon a police officer's orders. As Sugan tries to get more information, a female cop (Uma Riyaz Khan) stops Maya from telling the truth and later kills her. Back at home, Sugan gets a message from the female cop, which makes him realize that she is not a police officer but an assassin. Her next victim is no one other than Varalakshmi (Madhumitha), Sugan's sister. At the temple, Sugan's friend, brother-in-law Subbu (Subbu Panchu), and Varalakshmi are in a car accident, and the female assassin captures Varalakshmi. Sugan gets a call from Vijaykrishna that he needs Varadharajan alive so that he can give Varalakshmi back to Sugan.

Sugan decides that Parasu should impersonate Varadharajan alive, since the real Varadharajan is dead. He comes there with Parasu but finds the assassin trying to kill Sugan. Vijaykrishna wants Varadharajan back, but it was not him who called Sugan. Sugan and Vijaykrishna get into a fight along with Sampath, who gets in a fight with the hit-woman. Another police officer, ACP Vikram (Prem), kills the female assassin and returns Varalakshmi safely. A few days later, at Varadharajan's funeral, Sugan learns the truth about Varadharajan's death. Avinash was in love with Varadharajan's daughter for money only, but Sugan and Parasu stopped their love on the way to the new branch opening. Avinash uses his brother to get his love back by bringing Sugan and Parasu using Maya, and that Maya used drugs to make Sugan and Parasu very drunk. Then, the assassin comes by, killing Maya so that she does not tell the truth to Sugan. Sugan figures out that it was no one other than Vikram, Avinash's brother, who was behind everything. Soon Riyaz and Vijaykrishna also find out the truth. Riyaz tells Sugan to kill Vikram, Sugan fights with Vikram, and they both fall from the office into the swimming pool below. What happens to either of them is unknown.