Kochadaiiyaan opens with a prologue that tells us that the two kingdoms, Kottaipattinam and Kalingapuri, have been at war with one another for generations. We see a boy from Kottaipattinam, who is about to drown, being rescued and the boy, Rana, grows up to become a soldier in Kalingapuri. He earns the friendship of the prince Veera Mahendran, and is made the general of its army. He seeks the king's permission to attack their enemy nation but on the battlefield, Rana reveals himself to be the son of Kochadaiiyaan, the famed general of Kottaipattinam and admits that he enacted a drama to rescue...