Sujitha "Suji", a computer science teacher at Arasan High School, files a missing complaint about her student Ramya with the local police station. When her complaint is met with inaction, she escalates the issue to the
DGP, highlighting a pattern of missing women in the village. Suji's complaint also implicates Malaiarasan, the school's correspondent and head of the Cooperative society, and his brother Kottaiarasan, an illicit spirit manufacturer. The DGP appoints a special officer, to go undercover as a PT teacher at the school. Saravanan joins the school, where he works alongside Singaram, another PT teacher. Singaram, who harbors a one-sided love for Suji, tries to win her over by buying alcohol for her grandfather, Agasalingam. However, when Suji beats Malaiarasan's henchman, Amaldass, for harassing her, Malaiarasan confronts Suji and attempts to molest her. Fortunately, Mutharasu, Malaiarasan's nephew and a diligent student, intervenes and saves Suji. Later, at a bar, Agasalingam challenges Malaiarasan to a fight, but Singaram cowardly flees. Saravanan steps in, beats Malaiarasan and his men, and saves Agasalingam. Suji recognizes Saravanan as the hero who fought off her attackers. Suji soon realizes that Saravanan is likely the undercover police officer sent by the DGP to investigate the allegations against Malaiarasan and Kottaiarasan. Saravanan, concerned about the students' welfare, secures sponsorship to provide shoes for them. Alongside the new Maths teacher, Nadimuthu, he investigates the use of drugs in the school. At night, Saravanan surveils the operations of Malaiarasan's brothers, noticing their illicit activities. When a student named Gokul falls from a building and is severely injured, Saravanan rushes him to the hospital. Suji follows Gokul's classmate to the hospital, who witnessed the incident. It is revealed that Gokul's injuries were not an accident, but rather a result of Kottaiarasan's attempt to cover up his illicit activities. That night, Saravanan disguises himself and attacks Kottaiarasan's illicit spirit factory, brutally beating his men and burning down the factory. Meanwhile, Singaram is manipulated by Pattasamy into kidnapping Malaiarasan's nephew, Muthu, to repay his losses. However, Singaram's attempts fail. Suji discovers a watch she had gifted to Ramya in another student's hand. She informs Muthu about the watch and they both leave together to enquire about the watch, which Saravanan observes. Saravanan captures two students using drugs in the school and discovers they are linked to Muthu, who supplied the drugs. They also reveal that Muthu killed Ramya after she found him secretly recording nude videos of girls in the school bathroom. Ramya was the daughter of Thaiyamma, the housemaid at Malaiarasan's house. Saravanan rushes to save Suji after realizing Muthu's true nature. Muthu takes Suji to his brick kiln, planning to burn her alive to stop her inquire about Ramya. Saravanan arrives just in time and beats Muthu's men. Shockingly, Saravanan forces Muthu to call his father, Mudiarasan, who is believed to be dead. Mudiarasan arrives from abroad to visit his son, who has fallen into coma. The truth about Nadimuthu, the maths teacher, being the undercover police officer is revealed, raising suspicions about Saravanan's identity. Saravanan shares his past, revealing a personal vendetta against the Arasan brothers. Saravanan's wife, Madhavi, was a personal assistant to Minister Maasilamani. One day Madhavi discovered her pregnancy and tries to inform it to Saravanan as surprise. It is revealed that Saravanan is not a cop but a civil engineer. Meanwhile Mudiarasan, Maasilamani's right-hand man, planned to loot 100 crores in black money with Madhavi's help. However, Madhavi resisted, and Mudiarasan brutally killed her. Maasilamani was misled into believing Madhavi and Saravanan were involved in the loot, leading to Saravanan's imprisonment and torture. Now, Saravanan seeks revenge and teams up with Singaram, Nadimuthu, and Pattasamy to loot the 100 crores from Mudiarasan. Suji joins them, seeking justice. The 100 crores are stashed in a locker with a key split into three parts. Saravanan has two parts, and they plan to retrieve the third part. They tempt Malaiarasan's henchman, Amaldass, with alcohol and record his confession. Amaldass joins their side, and they plan to kidnap Charles, a service engineer from Bombay, to open the locker. Singaram pretends to be Charles to repair the locker. Meanwhile, Saravanan plants a spy camera in Charles' toolbox to gather information and devise a plan. Mudiarasan brothers discover Nadimuthu's true identity as an undercover police officer but they spare him, believing he's harmless. To obtain the third key piece, Saravanan and Singaram sneak into Mudiarasan's house at night, facing several obstacles along the way. They finally retrieve the key piece from Mudiarasan's waistchain. The team assigns duties for the heist: Nadimuthu spoils the popcorn machine, allowing Saravanan to enter as a service person; Singaram diverts the CCTV in charge; and Suji replaces the CCTV footage with the previous day's recordings. However, the fake threat call to theatre manager Soori fails. Saravanan fights off security guards, while Singaram and Nadimuthu distract Malaiarasan. The team accesses the vault, and Saravanan uses a bomb and motor-powered belt conveyor to lift the stashed cash through the ceiling. Meanwhile, Mudiarasan learns about Saravanan's connection to his son's murder and the attacks on his brothers. At the theatre, Singaram uses snake charmers and other distractions to keep the theatre crowd occupied during the heist. Just as the heist concludes, Minister Maasilamani and the police arrive, catching Mudiarasan and his brothers off guard. The team, except Saravanan, escapes the theatre safely, but they're worried about Saravanan's fate and the looted money. Nadimuthu later realizes that the money was hidden inside an air-filled cutout of the actor
Vishal as the theatre was screening the film
Madha Gaja Raja. Months pass, and the team is still struggling financially, with no news about Saravanan making them feel betrayed, believing Saravanan to have escaped with the loot. Nadimuthu visits the prison to learn more about Saravanan's true identity and learns that the real Saravanan is still in prison and the one who led the heist is the fake one. Just as they're discussing, each of them receives a refrigerator containing their share of the looted money. The fake Saravanan had also bailed out the original Saravanan. Meanwhile, the fake Saravanan receives a tip about 200 crores in black money in Goa, setting him up for his next heist. Maasilamani and his men brutally torture Mudiarasan and his brothers, determined to extract information about the money, and for killed Madhavi. == Cast ==