Diwan

Raghavan and Velu work as cooks in a non-veg hotel. Raghavan falls for Geetha, the daughter of a rich man, but her father insults him as a poor man. He challenges Geetha's father that he will be rich within a year to prove his worth.

Aishwarya, from a rich family, runs away with her driver Raju. Raju flees after a bad dream that he will be killed by her family, and he disappears. Dinesh offers to help them, but Raghavan understands Aishwarya's plight and decides to assist.

Raghavan confronts Dinesh and his men to shield Aishwarya and Meenakshi. He defeats them and escapes with Meenakshi to Rajapalayam. The pursuit intensifies as Kandhavel's shadow looms over the fugitives.

Raghavan arrives in a Tirunelveli village where locals nickname him Duraisingam. A woman reveals he is the grandson of the benevolent Duraisingam, prompting a flashback into his ancestor's life.

Duraisingam is portrayed as a benevolent helper who aids the poor. He clashes with Kandhavel, a gangster who aims to become minister. Duraisingam refuses to kill him because he promised his wife she would never become a widow.

When Kandhavel loses the election, he orders Duraisingam's murder by his men. Duraisingam fights to protect his family while trying to honor his vow to his wife. The violence around him escalates, testing his resolve.

Duraisingam's sons are killed and the baby of his older son goes missing; the baby is later revealed to be Raghavan, tying past and present destinies.

Duraisingam defeats Kandhavel's brothers and cuts Kandhavel's right hand before surrendering to the police. He upholds his ethics even as he yields to the law.

After the flashback, Raghavan visits the jail only to learn that Duraisingam had died years earlier. The revelation deepens his sense of belonging to Duraisingam's legacy.

Kandhavel grows furious after Dinesh dies from injuries sustained in Raghavan's clash and orders a hit on Raghavan and Meenakshi. A tense pursuit follows as the targets try to stay ahead of Kandhavel's men.

During a car chase, the attackers' pursuit ends near a riverbed, and Raghavan and Aishwarya escape with Meenakshi to the defunct mill of her family.

Inside the defunct mill, Raghavan pretends to kidnap Aishwarya and demands ransom from her family to force the truth to surface. Meenakshi's father and relatives locate them, beat Raghavan, and apologize after learning the truth from Aishwarya. Kandhavel and his men arrive for a final fight, but Raghavan defeats them and spares Kandhavel out of respect for Duraisingam's vow. In the end, Aishwarya marries the groom chosen by her parents, and Raghavan is reunited with Geetha.