Gopinath or Gopi (Gemini Ganesan) works at the Collectorate. He lives with his wife Jaya (Jayanthi), three children, and father-in-law (S.V. Sahasharanamam). A new collector takes charge and Gopi is shocked to see Janaki (Sowcar Janaki) as the new collector. His past life is revealed...
Ten years ago, Gopi and his parents go on a pilgrimage to Kasi where he meets and falls in love with Janaki, daughter of a Tamil teacher (V S Raghavan). Gopi and Janaki secretly marry and her father reluctantly accepts it. Gopi's mother pretends to accept, assures to take Janaki to Chennai, and sends Gopi for his IAS examination to Delhi. Later she refuses to accept Janaki and leaves for Chennai without her. She informs Gopi that Janaki died while bathing in the River Ganges. Gopi does not trust her words and goes to Kasi in search of Janaki. The new tenant who has occupied Janaki's house explains but Gopi fails to understand the language and assumes she is dead and returns to Chennai. After a few months, Gopi's mother convinces him to marry again and he marries Jaya. Gopi's attempts to tell the truth to Jaya about Janaki fail.
Janaki's father's effort to get her married again fails when he realizes that Janaki is pregnant. He then decides to make her an IAS officer and take revenge on Gopi. Janaki studies hard and becomes a respected IAS officer and lives with her father and son Ramu. Seeing Gopi at the office was a shock to her as well.
Janaki still respects Gopi as her husband, which disturbs Gopi. Gopi explains his attempt to find her. Janaki though not fully convinced, continues to treat him with respect leading to gossip at the office. Babu (Nagesh), one of the clerks makes an anonymous call to Jaya and informs her of Gopi's intimacy with Janaki at the office and she gets disturbed. Janaki's father, still nurturing hatred for Gopi decides to take revenge. With the help of one of the clerks, he creates a lot of problems, and ultimately Gopi gets suspended. Meanwhile, Jaya's elder son Prabhakar and Janaki's son Ramu become close friends and Prabhakar keeps visiting Janaki's house. Janaki encourages him and offers financial help through him. However, Jaya rejects it and becomes more suspicious of Janaki's intentions.
Meanwhile, Janaki finds out that Gopi is innocent and that they were frivolous complaints. Gopi is restored in his job. He seeks to leave for three months so that he can resolve his personal issues, which Janaki refuses. A disturbed Gopi loses focus and concentration at work and gets into trouble again. Gopi offers to resign but Janaki resolves the problem and advises him to manage his life well. A frustrated Gopi plans to attack her but realizing her good intentions apologizes. Janaki's father calls the Police but Janaki rescues him.
Janaki calls Jaya for the "kolu" (exhibition of dolls during Navarathri) at her home. Jaya attends and through a song, both explain their respective roles in Gopi's life. Disturbed by Janaki's open expression, Jaya's father writes to the CM seeking action against Janaki. The CM calls Janaki for a meeting and makes mention of the complaints in a subtle manner. Janaki assures to resolve her personal issues. Jaya gets an anonymous call that Janaki and Gopi are getting married. She concludes it to be true and attempts suicide and is saved by her father. Meanwhile, Janaki goes with the Police to take on the smugglers. Janaki gets shot and on her request, the Police rush her to Gopi's house. She requests Gopi to permit her to take treatment there. By then, Jaya arrives with her father and is shocked to see Janaki with Gopi. Janaki then reveals the truth that she is Gopi's first wife. Jaya now reconciles to the reality and accepts Janaki as her sister and asks her to live with them.
Meanwhile, Prabhakar who is playing with Ramu near a swimming pool accidentally falls in and almost drowns. Janaki's father refuses to save Prabhakar and an agitated Ramu jumps into the pool to save Prabhakar. Finally, Janaki's father jumps into the pool and tries to save them, but ends up saving only Prabhakar.
Ramu dies at the hospital. Gopi rushes to the hospital with both Jaya and Janaki. Janaki is devastated. Her father apologizes to Gopi for his misdeeds, which caused the loss of his grandson. At the same time, Janaki gets a letter deputing her to the United Nations. She accepts it and decides to move on when Jaya offers her son Prabhakar and Janaki happily accepts him. She leaves with her father and Prabhakar to take on the new job.
[from the book Pride of Tamil Cinema: 1931 to 2013 by G Dhananjayan, Blue Ocean Publishers, 2014]