Bitti (Kriti Sanon) is a young contemporary girl in Bareilly, Uttar Pradesh, who works in the complaint department of the local electricity board and is the apple of her father’s eye. Like most Indian mothers, Bitti’s mother wants to see her daughter get married to a nice man from a good family. Bitti, however, wants a husband who understands her and, more importantly, who accepts her exactly the way she is. A suitor comes but after knowing his disgusting mindset, she lies about not being a virgin and gets rejected. Her mother gets irritated with the constant rejections, but her father understands her. She gets heartbroken after hearing her parents conversation and later pours her heart out before her father who consoles and cheers her.
That night, despite having nowhere to go, she leaves her house and boards a train. While on a train platform, she chances upon a book at a bookstall and buys it. As she reads the novel entitles Bareilly Ki Barfi, Bitti starts to identify with the protagonist. Having found acceptance in the pages of the book, she decides to return home the same night. She longs to meet the writer and thus one day decides to search for the supposed writer of the book, Pritam Vidrohi (Rajkummar Rao). She goes back to the same bookstall where she had brought that book and asks about its writer. The bookshop owner directs her to Chirag Dubey (Ayushmann Khurana), who owns a printing press and who helped publish the book.
What Bitti doesn’t know is that Chirag is in fact the true author of the book. He had written that book five years previously, after undergoing pain when his girlfriend ditched him and married someone else. He wrote that book describing his girlfriend Bubbly and their love story. Since giving his own name as the writer might destroy his ex-girlfriend’s reputation, he coaxes one of his meek, so-called friend “Pritam Vidrohi” to have his name as the writer of the book. Vidrohi agrees but gets so scared of the possible future scenarios, that he leaves the city without telling anyone. He need not have been so worried, because in the five years since the book had been self-published by Chirag, not a single copy had ever been sold, except the copy that Bitti had purchased on the railway platform that day.
Bitti tries to get Vidrohi’s whereabouts from Chirag but Chirag successfully manages to convince her to write letters to the author instead of meeting him personally. She writes a letter to Vidrohi for Chirag to pass on to him. Chirag, being the true author, writes back and passes it off as Vidrohi’s response. Thus begins a correspondence between Bitti and ‘Vidrohi’. In the meantime, Chirag and Bitti get to know each other better and become good friends. Bitti, however, starts to lose patience when Vidrohi, despite her repeated requests, refuses to meet her. She broaches this with Chirag and implores him to arrange for her to meet Vidrohi just once. Chirag agrees and as he has fallen for Bitti and decides to tell her the truth, that he is the actual writer. But later he learns that Bitti’s mother hates that writer for spoiling their daughter’s mind and thus decides not to tell the truth, instead search for Vidrohi and make him the scapegoat.