Set in Agra, the story revolves around Simar Narayan and Reema Narayan, two sisters with different personalities. While Simar dreams of becoming a singer, Reema aspires to be a model. Aarav Oswal and Vivaan Oswal are cousins who love and respect each other. They fall for Reema, but Simar falls for Aarav. Reema is chosen to be Aarav's bride but leaves on the wedding day for an event for her modeling career. Because of this, Simar has to marry instead of her sister, but the Oswal family does not accept her as a daughter-in-law .Then Rima and Vivan held a wedding without telling anyone. After a lot of twists and turns, the Oswal family and Geetanjali Devi (Badi Maa) finally accept Simar as their daughter-in-law.
However, Simar and Aarav's relationship is jeopardised when Aarav's old friend Dhami enters their lives. Dhami is obsessed with Aarav and claims to be his first wife. It turns out that Dhami is mentally unstable and she drugs Aarav to marry her. Simar tries to expose Dhami but all her plans backfire. On Geetanjali Devi birthday, Dhami shows a picture of Gopichand Oswal (Geetanjali Devi late husband) and his second wife who is actually Simar's music teacher, Yamini. Simar leaves her musical career for Geetanjali Devi. Dhami decides to commit suicide with Aarav. However, Simar saves Aarav, while Dhami died after falling off the cliff.
Reema leaves The Oswal's mansion to complete her modeling career. However, when she returns, she starts acting strangely. Simar worried about Reema's behaviour. She decides to investigate and finds out that Reema has been captured by a yaksh named Rudra, and the one pretending to be Reema is actually Chhaya, her lookalike and Rudra's wife. Simar frees Reema and brings her back. However, it turns out that Chhaya had swapped places with Reema. Rudra learns that Simar is the reincarnation of Rani Yakshini Damini, the most powerful yakshini. Rudra tries everything to prevent Simar from remembering her past and attaining the power of Damini. However Simar gains the power and kills Rudra.
On their first wedding anniversary, Aarav wants to gift Simar something special. He saw a bangle which was in a statue's hand. The statue has a burn mark on it so no one was willing to buy it. However, Aarav likes it. The statue turned out to be cursed. It killed everyone one who hated it. Reema knows about this after some research that the statue was made by a man named Arindam, who was the heir of a famous Bengali family, The Roy Chaudary's. Arindam was in love with a maid named Labuni. However, The Roy Chaudary's refused their relationship and threw Labuni into fire. Labuni escaped but her face was scarred. Arindam had made a statue similar to Labuni and now Labuni's soul resides in the statue looking for someone who would love her despite the scar on her face. The man happened to be Aarav, and Labuni plotted to marry him to become alive. Labuni tries everything she can to marry Aarav. However, Simar manages to burn the statue. Labuni returns in her human form to marry Aarav. She becomes Geetanjali's maid and frames Simar for a murder. Aarav proves Simar is innocence and kills Labuni. Arindam, who falls for Simar, along with his grandmother and Dulba plan to bring back the dead Choudhary family souls into the bodies of the Oswal family but end up being defeated, thanks to Simar.
Gajendra (Aarav's father) had a daughter named Masoomi, from his girlfriend before his marriage with Sandhya (Aarav's mother). He had been raising her secretly in an orphanage for 25 years. A priest told Geetanjali Devi about a sin committed by one of the family members. To repent for the "sin", Geetanjali Devi distributes food to an orphanage which happens to be the same orphanage where Masoomi stays. Gajendra's truth comes out and everyone hates him except Simar. Masoomi overhears the conversation between Gajendra, Simar and Aarav. She learns about her father and runs away after Gajendra says that he will leave Masoomi for his wife and children. Masoomi meets Sandhya on the road who brings her to The Oswal's Mansion. Sandhya becomes heart-broken after learning the truth and keeps her distance from Gajendra. Masoomi accuses Aarav of snatching her happiness by stealing her father. Simar visits the orphanage to learn more about Masoomi. She learned that Masoomi had a twin sister named Gunjan who had died. Charulata (Gunjan and Masoomi's mother and Gajendra's ex-girlfriend) is a witch. She summons Gunjan's spirit to avenge The Oswals. However, Simar manages to defeat them. But Gunjan already orders a Naag[additional citation(s) needed] to disguise as Aarav.
The Naag possess Aarav's body to live longer. Simar manages to kill the Naag and free Aarav. However, Naag's wife, Nazar returns to seek revenge. She murders Sandhya. Simar performs a ritual to protect their house from any evil spirit. Nazar manages to break that protection and tricks Aarav into believing that they slept together. Simar reveals to the family that she is pregnant. Many months pass and Nazar enters the house also revealing to everyone that she is also expecting Aarav's child. Simar breaks down on this revelation and goes into labour pain. Nazar too stars experiencing labour pain. A Baba tells Geetanjali Devi that if Simar's child is born between 4:00–4:07 pm then that child will be the cause of Simar's death. Simar gives birth to a daughter at 4:06 pm. Nazar gives birth to a daughter as well and named her Amrit. Aarav snatches away Simar's daughter revealing that she is bad luck. However, Simar makes it clear that if her daughter is being thrown then she will also leave the house. It is revealed that Nazar exchanged the babies. She feels confident that she snatched everything from Aarav and Simar and permanently separated them. To her shock, this was a plan of Simar and Aarav and they successfully acquire their daughter from her when Nazar thought that now no one can challenge her. Nazar, held captive, reveals it to everyone that Aarav is not Amrit's father, but her Naag Devta (Snake God) gave her a blessing and made her pregnant. Nazar is burnt to death. Simar names her daughter Disha and adopts Amrit. The family accepts the babies and they are happily reunited.
