Prabhu, an orphan, is brought up by his friend Murali's mother and is the general manager for Murali's marketing agency at Madras. Murali treats Prabhu not just as a friend, but as a brother and depends on him for all business decisions. Prabhu is in love with Padma, a college student. Padma's relative Jayanthi is a young widow who works at Murali's office. Murali, an alcoholic with a roving eye, is not aware of Prabhu's love for Padma. Padma is the only girl who rejects Murali's advances. Though Jayanthi knows about the love affair between Prabhu and Padma, Prabhu's presence stimulates her sexually. Once she accompanies Prabhu and Padma for a film screening and unable to control her sexual feelings, comes out. Murali offers her a lift in his car; both get excited in the privacy of the car, but suddenly feel guilty about the incident.

A disturbed Jayanthi avails leave and goes to her village and Padma joins her, as Prabhu goes on an official tour. Prabhu, planning to surprise Padma, proceeds to Jayanthi's village to meet Padma. When Prabhu lands at Jayanthi's home, she is alone as Padma has gone to attend a wedding in a nearby village. Jayanthi convinces Prabhu to stay back overnight, so that he can meet Padma the next day. Jayanthi arouses Prabhu in the night and they make love. Prabhu, feeling guilty about the whole event, writes a letter of apology to Jayanthi and leaves. Devastated to read the note when she returns to Jayanthi's house, Padma returns to Madras, where she starts distancing herself from Prabhu without revealing why.

Murali continues to pursue Padma. When she falls down, he saves her and gets her admitted in a hospital, impressing her father. Murali happily informs Prabhu about his feelings for Padma; being a good friend and grateful for the help given by Murali's family, Prabhu remains silent. He accompanies Murali's mother to formally propose Murali's marriage with Padma. Padma's father accepts the proposal, and Padma remains silent. When Prabhu confronts her, she reveals that she had read his letter to Jayanthi, who is carrying his child. Shocked with the news, Prabhu leaves Madras without informing Murali and his mother and they feel upset thinking Prabhu is angry with them. Later Jayanthi writes a letter to Prabhu informing him of her pregnancy. Murali reads the letter and now knows why Prabhu left abruptly. Enraged, he severs ties with Prabhu then and there.

Prabhu searches for Jayanthi and finds her in Bangalore. He makes arrangements to marry her, but she has an accident. Before she dies, he ties a thaali around her neck, giving her the dignity of a wife. He relocates to Ooty. Meanwhile, Murali and Padma's wedding is postponed, as Murali falls ill and is advised rest by his doctor. He and Padma come to an estate on holiday, unaware that Prabhu works there. Prabhu meets them without realising that Murali knows about him and Jayanthi and apologises to Murali for leaving their home suddenly. While Murali is in no mood to forgive him, Padma, on learning that Prabhu married Jayanthi before she died, forgives him and tries to become close to him again.

Murali sees Padma and Prabhu together. Enraged, he takes Prabhu to a cliff; when he is about to shoot him, Padma reveals that they were originally in love and how they broke up due to Jayanthi's interference and Prabhu's honourable act in making Jayanthi his wife and legitimising their child, before she died. Murali and Prabhu reconcile, and Murali presents Padma to Prabhu as he knows they truly love each other, and leaves for Madras.