Samurai

Thiyagu, a medical student, is traveling to meet his childhood friend Varadharajan. He encounters Deiva, a kind-hearted but mischievous schoolgirl who lives with her grandmother and is the daughter of police officer Sandana Pandian. Sandana briefly confronts Thiyagu, but soon recognizes that his intentions are good.

Thiyagu and his friends kidnap a politician involved in illegal activities. During the operation, he learns that Sandana's family are neighbors and longtime friends with his associates. Sandana is appointed to investigate the case.

Thiyagu also abducts five more people, expanding his vigilante campaign. Sandana struggles to catch the culprit while the investigation intensifies. The case thickens as more victims surface.

Nisha's friends try to molest Deiva, forcing her to seek safety with her parents. Sandana is overwhelmed by the ongoing investigation and reluctant to listen to Deiva's problems. Thiyagu helps ease Deiva's anxiety by teaching her how to avoid such situations in the future.

Deiva, not knowing Thiyagu's true identity, develops feelings for him. She admires his courage and kindness amid the turmoil. The romance grows without her realizing who he really is.

Kavitha, Thiyagu's studious classmate, keeps a diary of the things she wants to tell him. She discovers that a pharmaceutical company distributed expired medicines that caused a boy's death. When she tries to expose the company, she finds little support and ultimately commits suicide, asking Thiyagu to deliver justice.

After reading Kavitha's diary, Thiyagu and his friends decide to exact vengeance on those who exploit legal loopholes to complete prison sentences by staying in guest houses and hospitals. They plot to pursue justice outside the conventional system.

In the present, Sandana identifies the next target as a minister behind the pharma crimes and tries to safeguard him. The minister is kidnapped anyway, and Sandana realizes Thiyagu is behind the abductions. This revelation deepens the conflict between Sandana and Thiyagu.

Pandian captures Thiyagu and puts him on trial in an open court with magistrates and spectators. Thiyagu demands that the kidnapped people be punished, insisting on capital punishment. The trial tests the dimensions of law and vigilante justice.

The magistrates deny the request for capital punishment, noting there is no law for it. The abductees are released, and a protest erupts; in the chaos, the mob kills the abductees. The scene underscores the perils of extrajudicial justice.

Sandana takes Thiyagu and his friends away in a van and praises his actions. She argues that there is a need for a law that grants the death penalty to certain criminals. Her stance reframes the debate about justice in the wake of the trial.

As Thiyagu leaves, Deiva arrives and tells him that Kavitha is always with him, just as Deiva will be. Her words link Kavitha's tragedy to Thiyagu's ongoing mission. The moment deepens the emotional stakes for all involved.

Thiyagu and his friends depart with Deiva, continuing their journey. Deiva's steadfast presence hints at a future where love and justice intersect. The story closes on their exit together.