Thotta

When Shanmugham and his mother arrive in Chennai to find his father, they discover he is living with another wife. In the ensuing confrontation, the father kills this second wife, and the chaos causes Shanmugham's mother to die as well. This brutal act shatters the family completely and hardens Shanmugham's resolve to survive at any cost.

The auto driver named Dhamu intervenes after Shanmugham's mother dies. He helps cremate the body and gives the boy a small amount of money, urging him to return to his own city and start anew. This act of kindness becomes a defining moment for Shanmugham, later revealed to be the father of Nalina, the girl he falls in love with.

The timeline notes this as planting a seed of gratitude that later connects to Nalina.

Growing up alone on Chennai streets, Shanmugham learns that the world favors those who bend rules. He gets pulled into corrupt police work, specifically working for DCP Muthuvel, who uses him for illegal encounters. As he rises through the gangland, he earns the moniker Thotta (meaning bullet) for his fearsome reputation and blunt power.

DCP Muthuvel orders Thotta to attack a girl's face with acid as part of his criminal operations. However, Thotta discovers the target is Nalina, the daughter of the auto driver who helped him years ago. This revelation stops him from carrying out the attack and instead triggers his protective, romantic feelings toward her.

The timeline notes this moment complicates the assignment and marks a turning point in Thotta's morality.

Nalina dreams of becoming a police officer, and Thotta promises to use his influence as a future commissioner to help her achieve this goal. To clear the path, Thotta kills a minister who is a major rival to Chief Minister Manimaran, demonstrating how deep he is willing to go to fulfill her ambition.

When Nalina approaches DCP Muthuvel for the police job, he demands sexual favors in exchange for the appointment. This abuse of power forces Shanmugham to confront Muthuvel and leads to a breaking point between them, setting up their eventual confrontation.

Giri is Shanmugham's close friend who tries to leave the rowdy lifestyle by marrying Gauri and seeking a quieter life. Muthuvel kills Giri to break Shanmugham's connection to his old crew and to eliminate potential witnesses to his corruption. This act deepens the rift and intensifies Shanmugham's conflict with Muthuvel.

In the climax, Thotta orchestrates a confrontation against both CBI officer Prabhakar, who wants to capture him alive to expose the truth, and DCP Muthuvel, who wants him dead to cover up his crimes. The final showdown tests loyalties and determines whether Shanmugham can expose the corruption while surviving.

The ending leaves Nalina's dream of becoming a police officer unresolved. The story ends ambiguously, asking whether justice and love can prevail over the corrupt system, but the summary does not confirm whether she achieves her goal of donning the police uniform.

Thotta's relationship with Nalina begins when he is ordered to attack her with acid but discovers she is the auto driver's daughter. This connection triggers his protective instinct, which grows into love. Nalina shares her dream of becoming a police officer, and Thotta promises to help, deepening their bond despite the dangerous criminal world surrounding them.

DCP Muthuvel is a highly corrupt police officer who uses Thotta to carry out deliberate encounters, taking credit for each killing to march up the ranks toward commissioner. He manipulates Thotta as a pliant asset in his criminal operations, ultimately wanting Thotta dead to silence him when his crimes risk exposure.