Madras High Court barrister Rajinikanth is a tour de force criminal defence lawyer who has never lost a case. He is a self-made man with a rags to riches story. He is well respected by other lawyers and is a terror to his opponents in the court. His only unfulfilled ambition is the prestigious position of judgeship and has all the qualifications of being a judge, with an exaggerated ego being his only character flaw. Kannan is Rajinikanth's nephew who is brought up like a son by the childless Rajinikanth and his wife Chellamma. Rajinikanth tutors Kannan in law and wants his ward to be as successful as he is. Kannan is an antithesis of Rajinikanth; he is a loving, loyal, god-fearing man, who occasionally appears in pro bono cases as a public defender.

One day, Rajinikanth is shocked to learn that an undeserving lawyer Rangabashyam has been made the high court judge, instead of him. Meanwhile, a man named Mohandas murders his wife and beseeches lawyers to appear on his behalf and save him. Rajinikanth feels that the bar council has insulted his prowess in jurisprudence and decides to seek his revenge by gaming the system and getting Mohandas acquitted, despite the latter's clear guilt. Mohandas is acquitted by the court, thanks to Rajinikanth's expertise in law. This deeply hurts Kannan, who does not say anything at that time out of respect for his uncle.

Later, Mohandas's fiancé dies in her bathtub by accident. Mohandas is arrested under suspicion that he has repeated his crime. Rajinikanth appears on Mohandas's behalf again. But this time around, Kannan protests and walks out of the house to become the prosecution lawyer facing Rajinikanth, convinced that the loyalty to his profession supersedes the loyalty to his adopted father. In the climactic court battle, Kannan defeats Rajinikanth due to his meticulous preparation as well as Mohandas neglecting to mention a critical surprise witness. Rajinikanth is particularly infuriated when Kannan taunts him asking if he would like an adjournment to prepare to cross examine that witness. Rajinikanth's ego does not allow him to seek adjournment, handing Kannan the victory. His first loss proves too much to handle and an anguished Rajinikanth succumbs to death, just before Kannan brings him the news of his appointment as a judge.