Ravi (S.S. Rajendran) leaves his hometown in Tamil Nadu and comes to Amritsar city in Punjab. He falls down unconscious and is saved by Raghu (Sivaji Ganesan) who is a peon in a trading company there. Ravi requests Raghu not to ask about his past and Raghu requests him to stay with him.
Raghu receives a letter from his mother requesting money for his father's treatment and Raghu weeps over his inability and penury. He then gets an appointment letter from his company addressed to Ravi for the post of Assistant Manager. Ravi gets confused and Raghu explains that he had applied for jobs to various companies under different names and he got the peon job first. Now that he has received a letter addressed in the name Ravi, he forces Ravi to accept the job. Ravi borrows money and sends it for Raghu's father's treatment and Raghu feels overwhelmed by his friendship.
Mahadevan (S.V. Ranga Rao), a rich businessman, is depressed by false and baseless rumours that his elder daughter Kokila (Savithri) has a relationship with a rogue Varadan (M.R. Radha). Her innocent behaviour is mistaken for an unstable mind.
Meanwhile, Ravi's steno Latha (K.R. Vijaya) boldly expresses her love for Ravi, and Raghu meets her father (V Nagaiah), who readily accepts, as his late wife's desire was that Latha should marry a Tamil boy. He requests Raghu and Ravi to come and live in his house after marriage and they accept. After marriage, they live amicably in the same house.
Mahadevan continues his attempts to get Kokila married. However, the prospective grooms show more interest to marry her smart and educated sister Sakuntala (Pushpalatha).
Meanwhile, Raghu's parents accept Kokila's proposal which comes through their Advocate (S.V. Sahasranamam). His parents write to Raghu asking him to come and meet the bride. Overjoyed, Ravi and Radha advise Raghu to go and see his future bride and send them her photograph. Raghu reaches Chennai and on his way home his vehicle stalls. He gets a lift in Kokila's car and they start chatting. Kokila mentions how people talk ill about her character and that she got into issues with Varadan by innocently trying to help him. Raghu understands her innocence and feels bad about the happenings around her.
When Raghu and his parents come to see Kokila, Raghu agrees to marry Kokila, but asks for time to get his friend's consent and sends her photo to Ravi. Radha likes Kokila's photo but Ravi does not like her for some reason and replies to Raghu that Kokila is not suitable to be his wife. Raghu, who is already in love with Kokila, is shocked.
Raghu goes to Kokila's house with Ravi's letter and meets Sakuntala who shares the family's happiness with him on his marrying Kokila. Raghu shows the letter from Ravi and a shocked Sakuntala requests him not to disclose this to her parents. Raghu agrees and returns to Amristar. Sakuntala writes to Ravi, who is none other than her elder brother.
When Raghu reaches Amristar, Radha says that Ravi was shocked on seeing Kokila's photo. Raghu now understands there is some issue between Ravi and Kokila. At the same time, Sakuntala's letter arrives and Raghu reads it. He understands that Ravi is her elder brother who ran away when people spoke ill about Kokila. Raghu confronts him and Ravi accepts the truth but explains that he did not wish his best friend to marry Kokila, who is rumoured to have loose morals. Understanding and appreciating Ravi's true friendship, Raghu returns to Chennai.
In order to stop the wedding, Varadan meets Raghu's parents and talks ill about Kokila's character. By then Raghu arrives, thrashes Varadan and makes him confess the truth. Now, Raghu's parents are apprehensive but Raghu states that Kokila is pure and resolves to marry her.
At Kokila's house, the marriage arrangements are on. Mahadevan gets shocked when he happens to read Ravi's letter and scolds Kokila harshly for her behaviour. Raghu arrives and declares that he wishes to marry her immediately. By then, Kokila, upset with her father's harsh words against her character, has consumed excessive sleeping pills. Before she dies Raghu marries her to make her die as his wife. When Ravi arrives, Raghu regretfully tells him, how one can ruin a girl's life by talking ill of her character.
[from the book Pride of Tamil Cinema:1931 to 2013, G Dhananjayan, Blue Ocean Publishers, 2014]