Dev and Nithya two people from different strata of society ended up best friends from childhood. He belonged to the rich Goenka family while she was the daughter of the driver who worked for the family. Somehow the differences never affected their relationship. They went on having a warm platonic relation.
They both were carefree youngsters with simple dreams. Nithya dreams revolved round her family. She wanted to study, work and support her parents and little sister Payal. So were his. He wanted to fulfill his late father's ambition about him and was an obedient son to his mother. They never thought anything will come between their friendship and always promised to be together.
But what life had in store for them was different. A day came in their life when she became Nithya Mitra and he Dev Goenka. The barriers which she thought never existed she learned it the bitter way they existed. When Shaurya Goenka Dev's cousin raped her sister Payal Nithya's hopes of support were crushed when she received the email from her childhood bestie that he will be with family.
Trust was broken. Barriers came up and 2 years later when she came back as Durga to seek justice for her sister her hatred was most not for the man who raped her sister, but was for the man who broke her trust. Seeing him after 2 years brought out all the emotional pain in her which she had kept locked inside her and she gave him the worst curse. That he will be alone, always in pain and will never be successful for what he had done to her.
Dev on the other hand had come up with a guilty conscious. Burdened by his father's dreams and mother's expectation and his own's family's manipulation of facts he was trying to find out his Nithya and what happened to her. He had not intentionally cheated her, but in fact he had loved her which he had never confessed to her.
In his search of truth once again Dev and Durga's path clash. The besties who trusted each other like anything start of their relation based on mistrust and argument. Durga plans against Dev for punishing him for what he has done to her. She creates jealousy in Shaurya's mind by showing Dev as a competitor trying to win her heart. She enjoys the discomfort it creates for Shaurya. But the things turn a ugly turn when Shaurya plans to murder Dev and Durga comes to know from Gautham that Dev loves Nithya. He has come back for Nithya and help her in getting justice for Payal. Durga saves Dev from Shaurya's murder attempt but decides to go away from his life as her presence can be dangerous to Dev. She is just happy that Dev has not betrayed her and he was not the one who wrote the email.
Durga's decision to marry Shaurya doesn't go well with Dev because by that time he had developed a warm feeling for Durga. But her strong decision ends up creating further confrontations and misunderstanding between them. Durga go ahead with the plan to marry Shaurya and Dev go ahead with his plan of finding Nithya who he believes is hidden by Durga. Their relation detoriates to a point where Dev hates Durga. However on the day of wedding Shaurya rejects Durga and Dr Dayal force a deal on Dev. That if he marries Durga he will see Nithya on her birthday.
Dev marries Durga for reaching Nithya but continues to hate her. But she bears his taunts and sarcasms without complaining knowing fully well how much he loves Nithya and how much pain the forced marriage has given him. Things go completely wrong for Durga when she plans a confrontation with Raima and Sakshi on KC vrath party. Raima ends up speaking about Payal and Dev confronts her. Inorder to stop Dev from further pursuing things Durga writes a letter from Nithya and gives to him. But Dev getting a message from Raima that she will tell the truth goes behind her and ends up accused in murder attempt of Raima.
Durga decides to save Dev. In jail Dev meets Naveen Mathur and from him Dev knows the entire story of Payal rape case. He knows though Mathur had sent goons to kill her, before the goons could do anything to her she was involved in a deadly accident. He also understands whatever Durga is doing she is doing it to get justice for Payal and Nithya. In addition to that while in jail Dev and Durga rekindles their friendship and Dev notices many similarities between her and Nithya.
Once out of jail Dev goes to find more about the accident that Nithya encountered and his search shows that Dr Dayal was the one who driving the car which hit his Nithya. He confronts Dr Thakur about it and Dr Thakur tells him not to worry Nithya is alive. Dev tells he knows where Nithya is and he has understood where Dr Thakur has hidden his Nithya.
Dev feels happy after understanding Durga is infact his Nithya. But understanding her situation he gives her space so that she reveals it herself. On the other hand Durga feels uncomfortable with Dev's closeness as she thinks it can affect her mission she behaves rude, stays aloof and even tells her relation with Aakash is something more than friendship. Dev bears with it understanding her situation and her need to hide her identity.
Just like Durga didn't make a issue out of Dev's sarcasm and taunts , Dev also doesn't make much of her initial anger and current aloofness. He simply stands by her. But again things take a turn when Durga with the help of Aakash gets an old tape hidden by Sakshi and comes to know Rajnath had infact murdered Arnab Dev's father. Unknown to them Dev too sees it and in his fury goes to kill Rajnath. Durga stops him and involves him also in her battle for justice.
But Shaurya who was planning to kill Dev once again traps him and misleads him to a lonely spot. But before he could harm Dev, Durga comes there and takes the bullet which was fired at Dev. Dev calls her Nithya and Durga realizes Dev knows who she is. But she remain rude to him telling he should not call her Nithya as she is Durga. If she calls her Nithya he can stay away from her. Still Dev doesn't complain but support her in her mission.
Finally they succeed in giving justice to Payal but Durga has to undergo a surgery as she had developed a clot in her brain due to the fall. Once she is cured Dev tells her he understands his Nithya wants to stay with her sister Payal. He tells her he has no problem about it and she shouldn't stress thinking about anything. She is free to go as anyways their marriage was a deal.
Durga goes to him and tells she had told him umpteen times not to call her Nithya. He should be calling her Durga only and he needs to develop that habit. To a bewildered Dev she tells Nithya was his best friend, but Durga loves him a lot. She goes to him and they hug each other warmly showing irrespective of the challenges the world threw at them, irrespective of many things that came between them, irrespective of hating each other though over a small period of time , depth of their friendship and love ensured that they face everything successfully and once again come together for eternity.