The film opens with Kaber Vasuki as the narrator, guiding the audience through a Chennai city where ambition and danger intertwine.
Anand alias Bruce Lee, a college graduate, lives in Chennai and trains in martial arts with a tight-knit circle of equally jobless friends, resisting the pull of a conventional 9-to-5 life. As he tries to recruit new students to keep their school afloat, he finds himself drawn into a street brawl and into a budding romance with Shakthi, the daughter of DCP Gaurav.
Across the city, a rash of burglaries erupts, leaving dozens dead and vast sums stolen. The police sense that a new robbery is looming, and Anand’s grandfather urges him to present himself as a hero so Shakthi can see him in a brighter light.
To win her attention, Anand borrows a superhero costume and steps into the mantle of Mugamoodi, hoping to impress Shakthi. He tries to dazzle children with his flashy skills, but his masquerade lands him squarely in the middle of a police chase. He aids the cops in capturing one bandit, only for the gang to shoot the captured suspect during transfer. News spreads that Mugamoodi has captured a suspect whom the police could not catch in months, and Shakthi begins to warm to the masked figure.
Gaurav uncovers a fingerprint match between the crime scene and police records, tightening the city’s sense of a looming clash.
Determined to be honest with Shakthi, Anand visits her unmasked to confess his love. On the way, a gang member shoots Gaurav; Anand struggles to intervene, but the gunman escapes after the weapon is seized. The family believes Anand is the shooter. He becomes a target of the police, and his friend Viji is killed during a visit to Shakthi. With Viji gone, Anand’s grandfather and brother fashion a new superhero costume, a sign that the vigilante path might be more than a fantasy.
Gaurav survives, but the gang intensifies its plan to kill him and his family in the hospital. Mugamoodi returns to protect them, defeating the gang and taking a file from Gaurav’s records that contains the latest findings, including the fingerprint match, as Anand seeks to avenge Viji’s death. The documents reveal a troubling truth about his martial arts teacher, Sifu Chandru, who is exposed as not being connected to those crimes.
Chandru then reveals a larger plot: Anguchamy, known as Dragon, is the true mastermind behind the crimes. Chandru and Dragon trained in the same school two decades earlier, tying their histories together in unexpected ways.
Meanwhile, Dragon learns that Mugamoodi is actually Anand. He and his gang raid Chandru’s school to kill Anand, but Chandru is nowhere to be found and is killed in the crossfire. The gang then seizes a port, kidnapping 30 children and three adults, including Shakthi, using them as hostages to force the police to secure a ship across the Indian border. They also demand that Mugamoodi drive a van of gold alone, threatening to kill the hostages if their terms are refused.
Anand agrees to the dangerous mission. A tense confrontation unfolds as he drives the gold; in the port, Dragon unmasks Mugamoodi and reveals Anand’s identity to Shakthi. Dragon also confesses that his brother Anthony had shot Gaurav earlier. With the help of his grandfather and friends who had slipped into the port, Anand eliminates key gang members. The final showdown between Anand and Dragon ends with Dragon falling to his death in the sea. The hostages are freed, and Shakthi tells Anand to continue his work as Mugamoodi.
