Naan

Karthik forges his friend's parent's signature on a report card and is sent home from school. He then discovers his mother in bed with a neighbor, and although she begs him to keep quiet, he reveals the affair to his father. The revelation drives his father to commit suicide, shattering the family.

As the illicit affair continues, Karthik kills his mother and her lover by setting the house on fire. The crime leads to his placement in a juvenile detention facility, where he spends years and hardens his resolve.

After serving time, the warden releases Karthik and urges him to focus on his studies. He is given the address of his uncle and advised to pursue a better path in life.

With his aunt unwilling to take him in, Karthik travels to Chennai to begin anew. He hopes to leave his violent past behind and forge a fresh identity.

On the journey to Chennai, a bus accident claims the life of fellow passenger Mohammed Salim. Amid the chaos, Karthik steals Salim's documents and adopts his identity.

Karthik enrolls in a government medical college by presenting himself as Salim. He befriends Ashok, Rupa, and Suresh, and Ashok offers Salim a place to stay as he settles in.

The warden from Salim's juvenile home recognizes Karthik, yet he continues to pose as Salim to avoid exposure. Ashok grows suspicious of the new friend as their bond deepens.

Ashok discovers a photo revealing Karthik's true background, triggering a tense confrontation. When Karthik is pressed about his identity, Salim shoves Ashok, who hits his head and dies. Karthik opts to cover up the murder rather than be exposed.

Karthik buries Ashok's body in a graveyard on the outskirts to hide the murder. He then impersonates Ashok, fooling Ashok's parents and Rupa by continuing to act as the son who disappeared.

Suresh uncovers Karthik's deception, and Karthik kills him, burying the body in the same graveyard. The police later connect Suresh's corpse to Ashok's disappearance, triggering a city-wide investigation.

During questioning, Karthik tricks the police into believing that Ashok killed Suresh and fled, while authorities regard Karthik—still living as Salim—as an innocent, hardworking student. He continues to live under Salim's identity, deepening his dual life.

The film ends on a cliffhanger as Karthik persists in living as Salim, even convincing Salim's father to back the deception. The unresolved fate leaves the story open for a continuation.