It is set in 16th-century Kerala in the northern region. The plot unfolds in the household of Puthooram Veedu, the house of great Kannappan Chekavar. Kannappan adopts the son of his estranged sister when the boy looses both his parents and brings him to Puthooram Veedu to live and learn with his cousins. The boy, Chandu, a quick learner, earns the love and admiration of his uncle, while he is loathed by his cousin Aromal. As they grow up Chandu is betrothed to Aromal’s sister, Unniyarcha. Several events unfold where in Chandu finds himself being pushed to the corner by his cousin and flees to further learn Kalari under the guidance of Tulunadan expert and master Chekavar, Aringodar. Chandu has to recount only losses in his life, as Aromal ensures Unniyarcha is not married to Chandu. He even deceives Chandu by usurping and marrying Kunjinooli, who was interested in Chandu. The heartbroken hero moves ahead and continues to master the art of Kalari Payattu from Aringodar.
Meanwhile, Chandu is still smitten with Unniyarcha and does not miss the boat when she invites him to her bedroom one full moon night. Chandu swims across raving waters and gallops miles across barren land to consummate his love. As Chandu and Unniyarcha get intimate in her bedroom, suddenly Unniyarcha’s husband, the eunuch Kunjiraman knocks the door. Unniyarcha, the clever vixen that she is, creates a mayhem and convinces her husband that Chandu broke into her room as she was awaiting the arrival of Kunjiraman and tried to misbehave. Chandu gets a sobriquet: ‘Penmohi Chandu’ or ‘Womanizer Chandu.’ A dejected Chandu finds solace in Kunji Aringodar’s daughter. One day, a feudal lord, Unnichandror arrives at the footsteps of Aringodar and invites him to represent his cause in an angam against a property feud with his brother Unnikonar. Unnikonar, in turn, invites Aromal to represent him.
Chandu is now caught in a dilemma, when his uncle requests him to play second hand to Aromal in the angam against his teacher Aringodar. His decision is made easy when Unniyarcha appears and offers to give herself fully to Chandu if he assists and helps Aromal win against Aringodar. A tempted Chandu, decides to second Aromal. Chandu takes on the task of revitalizing Aromal’s swords by providing them for treatment to the blacksmith. However, Kunji, Aringodar’s daughter, bribes the blacksmith and makes them brittle. On the day of the duel, the highly skilled Aromal is no match for the master Aringodar. To add to the misery, Aromal’s sword breaks in two. As Chandu placates an attacking Aromal seeking time out to replace the weapon, Aringodar obliges. Then wily Aromal throws the broken sword and kills an unguarded Aringodar. Aromal is declared winner. As he retires to his resting place, Chandu follows him to tend to his injuries. Aromal blames Chandu of cheating, by treating the swords to make them brittle, and attacks him. Aromal kills himself in an accident by falling over a sharp lamp. As people gather, Aromal breathes out his last words: “Chandu chadhichu” . The ill-fated Chandu escapes the mob and finds the blacksmith, who informs that he was bribed by Kunji. Amongst spectacular action sequences, Chandu storms into Aringodar’s household seeking Kunji. Again he is defeated, as he finds Kunji has commit suicide by hanging herself.
Chandu returns to Puthooram Veedu and is greeted by a raging Unniyarcha, who vows her sons will avenge her brother’s death. Years later, Aromal Unni and Kannapan Unni come to Chandu’s doorsteps seeking revenge. Chandu explains to them the situation, hoping to avoid a duel. They are in no mood to listen and insist on a duel to death. Aromal Unni exalts, “I, son of Unniyarcha, will die or go back with your head.” Chandu appears to relent and turns his back to them to bow before the deity in preparation for the duel. But in one final act of valour, Chandu stabs himself with a sword and utters his final words to Aromal as he dies, “You are my unborn son …” — his love for Unniyarcha still intact.