It is a remake of Bengali movie Kalankito Nayak (1970) starrer Uttam Kumar, Sabitri Chatterjee and Aparna Sen.
The film begins in a courtroom, where a lawyer labels a person as characterless, promiscuous and asks if he knows anyone by the name of Rosy.
On a trip to a mountainous area,Indrajeet Mukherjee (Inder) suddenly encounters heavy rainfall and takes shelter in the house of an old gentleman nearby, where he meets a girl named Rama.
As days pass, the bond between Rama and Inder grow stronger and it ultimately transforms into love.
In the evening, Ajit tortures Rama after failing to find her jewelleries which he aims to spend behind his promiscuous activities.
In the morning, Inder is shocked to learn that his mother has sent Rama on a train to Banaras.
Then he uses Rama's jewelleries to build his factory and quickly becomes a wealthy, thriving businessman.
On the day he decides to buy a house worth Rs.3 lakh, his mother passes her last breath.
Inder then moves to the house with his wife and his younger brother Debojeet Mukherjee (Debu).
The cunning Avinash successfully requests Inder to not include his name in the salary register, effectively ensuring that no written proof of his work in the company exists.
In Delhi, Inder learns that he has to convince a guy named Khosla to get his desired contract.
The ticket checker then informed her that they had left Banaras long ago and now they are in Kashi.
Taking opportunity of Inder's absence, Avinash steals all the money from the company's account.
In Delhi, Inder receives a telegram which informs him that workers have been protesting after not getting their wages.
Shocked, Inder returns to Calcutta and understands that Ajit has stolen all the money.
Ajit then denies every accusation and tells that legal actions can not be taken against him as there is no written proof of his work in the company.
Although Rama withdrew the money to help Inder, Avinash tricks Kamala and Debu into perceiving that Inder is depositing his business money into Rama's personal bank account.
Even Kamala is found to be alive, who spread the false rumors of her death so that Inder can live peacefully with Rosy.
Rama initially agrees but then decides to leave for good and give away her daughter to Inder and Kamala.
Suddenly Inder discovers a handwritten note by Rama, informing him of her permanent departure and requesting him to take care of Minu.
However, the scene is actually shot in Mumbai as one can see the Worli branch of State Bank of India when he walks out with Sharmila Tagore.