A car makes an entry into the village. An MP (V. K. Ramasamy) gets out of the car and finds that the village is self-disciplined in terms of cleanliness, and the villagers get rid of bad habits, such as drinking. He learns that the cause of all this is a young man named Udaymoorthy. The MP wonders how only a young man was able to achieve this and expresses this to Udayamoorthy; a flashback begins.

Adolescent Udayamoorthy, from a high society family, sees an old, blind beggar woman struggling to pick up a banana thrown by a passerby. Udayamoorthy doesn't help the woman, and an old man helps the beggar woman instead. The old man calls Udayamurthy and advises him to be helpful to others. The struggle of that elderly woman pinches his mindset due him not helping her in need. Now and adult, Udayamoorthy is a very mischievous and happy-go-lucky guy who likes to pull pranks on his family members and gets punished by his father Bilahari Marthandam Pillai, an ardent devotee and short-tempered Carnatic music singer. Pillai's elder son is born mute and hence had to take in instrument, the nadhaswaram, which he is quite adept at.

One day, Pillai shouts at Udayamoorthy, saying that it is better to die than to live an irresponsible life like this, and this hurts Udayamoorthy. The next morning, family members are shocked on seeing Udayamurthy hanging himself at the middle of the hall. But actually, it is another prank played by him, and he did not die so. Angayarkanni (Manorama), hurt by the mischief, feels sad for not playing her role as a sister-in-law and not raising Udayamoorthy properly and making him as an irresponsible boy. Udayamoorthy changes his mind and start to be responsible, making his family happy. He comes to a decision of being helpful to the society by reminding of the temple incident in his adolescent life and on seeing an old gardener who wants to live usefully for the society at least by planting trees.

Udayamoorthy sees a woman in a government office who protests against an official for rejecting her application for a teacher job for not mentioning her caste and religion in the application. Udayamoorthy again sees the woman at a theatre when she slaps a thug for misbehaving. Udayamoorthy gets attracted to the girl named Lalithakamalam (Seetha), on knowing that she and her thoughts are very much secular. Both Udayamoorthy and Lalitha fall in love with each other. Udayamoorthy could not concentrate on singing when he hears the begging of a night beggar. This angers Pillai, and he shouts that Udayamoorthy is not fit to be his disciple. Pillai also gets angry on seeing Udayamoorthy loving a girl who come from the caste of untouchables. Udayamoorthy and Pillai get into a fight when the latter brings another man Charukesi (Ramesh Aravind) to become his disciple, stating reasons that Udayamoorthy can live as a man going behind humanity and not as a devoted singer. At another incident, Udayamoorthy gets vexed when Pillai does not care to save a dying man by giving a lift in his car to the hospital but cared only to be punctual for his music program, leading to the man's death due to delay in treatment. Pillai challenges Udayamoorthy to become a man making his father proud without using the name of his father in the society and then he will listen to what he says. Udayamoorthy could not bear to be neglected by his father, and he leaves the house.

Udayamoorthy meets the dead man's wife and finds that the government did not give any compensation to the family as the man was drunk while on duty. Udayamoorthy finds a lot of men laying always at drunkard state and their children going for work to earn for their drinking expense instead of going to school. Hence he sets out to change the people and bring them out of drinking habit. He becomes unsuccessful in his attempt, and at the same time gets attacked by a liquor-selling group. Lalitha provokes the wives of the drunkards to protest their husbands, to which the women cooperate. Udayamoorthy gains the enmity of the drunkards for destroying the liquor shops and provoking their wives against them. Hence they set out to stop the wedding of Udayamoorthy with Lalitha by promising that they would stop drinking if he cancels his wedding, to which Udayamoorthy accepts. His sacrifice earns up the respect upon the whole village, and the drunkards start to obey him. Udayamoorthy and Lalitha together start 'Amaidhi Puratchi Iyyakam' (Silent Revolution Society) and bring many reforms.

The MP, on hearing the whole story, appreciates him a lot and brings the reformation to the light of the government. Udayamurthy becomes famous overnight and gets 'Best Indian' award from the prime minister for transforming the village in the good path. Pillai finds that his son achieved his mission and proudly announces that Pillai is Udayamoorthy's father, rather Udayamurthy is Pillai's son. He also accepts the marriage of his son with Lalitha and unites them.