A young boy named Rana, who hails from the kingdom of Kottaipattinam, leaves his family, despite his brother Sena pleading him not to do so. The boy soon meets with an accident while rowing in the river and is eventually discovered by some fishermen from the neighbouring kingdom of Kalingapuri, a rival of Kottaipattinam. Rana (Rajinikanth) grows up there and trains in weaponry, and grows up to be a fearless warrior. Due to his fighting skills and bravery, he soon wins the confidence of the king of Kalingapuri, Raja Mahendran, who promotes him as Commander-in-Chief of the Kalingapuri army. Rana’s first job as Commander-in-Chief is to free the soldiers of his hometown Kottaipattinam, who are being treated as slaves, enlist them in the army and train them. He then seeks the permission of Raja Mahendran to attack Kottaipattinam, to which the latter agrees. However, during the war, Rana encounters his childhood friend, crown prince Sengodagan, the son of Rishikodagan, king of Kottaipattinam. Immediately signalling an end to the war, he, along with the soldiers disown Kalingapuri and return to Kottaipattinam, much to the disgust of Raja Mahendran and his son, crown prince Veera Mahendran, who swear revenge on Rana for tricking them and betraying Kalingapuri.
At Kottaipattinam, Rana and Sengodagan renew their friendship. Sengodagan introduces Rana to Rishikodagan, who is alarmed on seeing him. Rana also reunites with his younger sister Yamuna Devi (whom he last saw as a baby) and their uncle, who raised her, but soon learns that his mother Yaahavi is dead and Sena is missing. He soon learns that Yamuna and Sengodagan are in love with each other. He accepts their relationship and decides to get them married, even cleverly convincing Rishikodagan, who was unwilling to get his son married to a girl of a non-royal family. Meanwhile, Rana also falls in love with his childhood sweetheart, princess Vadhana Devi, the daughter of Rishikodagan.
Soon, Sengodagan and Yamuna get married. But following the wedding, Rishikodagan disowns his son for marrying Yamuna despite knowing that the latter does not belong to a royal family. An unfazed Sengodagan immediately leaves the palace with Yamuna. Later that night, a masked man barges into the palace and attempts to kill Rishikodagan. Vadhana immediately goes after him, fights him and gets him captured. Rishikodagan unmasks the assassin who is revealed to be Rana, and immediately throws him into prison, sentencing him to death. An upset Vadhana rushes to the cell where Rana is imprisoned, where Rana tells her why he attempted to kill Rishikodagan.
Years ago, Rana is the younger son of Kochadaiiyaan, the former Commander-in-Chief of Kottaipattinam’s army. Kochadaiiyaan is extremely respected in Kottaipattinam for his bravery and exploits and is more popular than Rishikodagan himself. This made Rishikodagan jealous of Kochadaiiyaan. One night, when Kochadaiiyaan is returning by ship to Kottaipatinam with his army after buying horses and ammunition, they are attacked by the army of Kalingapuri. Kochadaiiyaan defeats them but allows them to return to their kingdom as an act of chivalry. However, the Kalingapuri army, before leaving, poison the food on the ship. The Kottaipattinam army men consume this food, and fall ill.
Despite knowing that he had been tricked by the Kalingapuri army, Kochadaiiyaan immediately rushes to Kalingapuri itself, because it is the only land body close enough to provide medicines to the sick and dying soldiers. He orders Raja Mahendran to provide medical assistance to his soldiers. Raja Mahendran, in turn, cunningly proposes a deal that, if he wants his men to be saved, he has to leave all the horses, ammunition and the sick army men in Kalingapuri as Raja Mahendran’s slaves. Only if Kochadaiiyan agrees to this, his soldiers will be nursed back to health. Kochadaiiyan thinks that his men rather be alive as slaves than die from poisoning, and also thinks that when they officially wage a war in the near future, all of them could be easily rescued. So he accepts Raja Mahendran’s offer and leaves Kalingapuri all alone. When he returns to Kottaipattinam, the jealous Rishikodagan seizes this opportunity to strip Kochadaiiyan off all respect and dignity and sentences him to death for becoming a traitor to Kottaipattinam by surrendering his army men, horses and ammunition to Kalingapuri. Though all his subjects are dismayed at Kochadaiiyaan being sentenced to death, and Yaahavi even goes to the extent of publicly rebuking Rishikodagan for his injustice, Rishikodagam stands firm in his decision. Kochadaiiyaan is executed the following morning before Rana’s eyes.
The story comes back to the present, with Rana telling Vadhana that he ran away to Kalingapuri, with the intention of freeing the soldiers of Kottaipattinam and to take revenge on Rishikodagan for unjustly killing his father. Vadhana is shocked on hearing about her father’s actions and reconciles with Rana. She then pleads with her father to release Rana, but to no avail. Meanwhile, Rana escapes from prison. When Rishikodagan learns of Rana’s escape, he immediately arranges for Vadhana’s marriage with prince Veera Mahendran after consulting with an astrologer and learning that his life is at Rana’s mercy. Despite the enmity between Kottaipattinam and Kalingapuri, he arranges this marriage with the hope that their united armies and their mutual hatred for Rana can subdue him.
On the day of the marriage, Rana arrives just when the marriage is about to take place. He and the people of Kottapattinam berate Rishikodagan for becoming traitor and surrendering the whole Kottaipattinam to Raja Mahendran for his own personal interests and commitments (this was the same charge which Rishikodagan had placed on Kochadaiiyaan years ago). Following this, a war starts between Rana and the united armies of Kottaipattinam and Kalingapuri. Rana successfully manages to subdue the armies of both kingdoms, he kills Raja Mahendran and allows Veera Mahendran to return as he was defeated, reminding him of their friendship. He then fights Rishikodagan and decapitates him.
Finally, as Rana and Vadhana reunite, a young soldier comes towards them riding a horse. This soldier is revealed to be Sena, and both the brothers reunite.
Kochadaiyaan
- Engae Pogudho Vaanam
- Medhuvagadhan
- Maatram Ondrudhan Maaradhadhu
- Manappenin Sathiyam
- Idhayam
- Engal Kochadaiiyaan Kochadaiiyaan Ensemble
- Manamaganin Sathiyam
- Rana’s Dream
- Karma Veeran
