Kayalvizhi Pandian, an upper-division clerk at the Valluvenpettai branch of the Madras Central Bank, is a fervent
feminist and
anti-Hindi imposition activist. She also writes stories under the male pseudonym "Ka. Pandian", as female authors are met with low readership. Previously, Kayal and her grandfather, Raghothaman "Raghu Thatha", had successfully shut down the Bharathiya Bhasha Ekta Sabha, a Hindi organisation run by Ranganathan in their village, a feat celebrated by the villagemen. Her parents are now pressuring her to marry soon, which she refuses. Kayal receives a promotion with two conditions: a transfer to the Calcutta branch and passing the Hindi Pratmika exam. Meanwhile, Dr. Chandrasekar recommends that Raghothaman undergo a
barium swallow test in town due to his stomach pain. The test reveals
stomach cancer, and Raghothaman begins treatment at the Madras Cancer Institute. Distraught, Raghothaman expresses three final wishes: to savour biryani at Buhari Hotel in Madras, take a photo with
M. G. Ramachandran, and see Kayal married. To fulfill her grandfather's last wish, Kayal reluctantly agrees to marry, despite disliking the suitors her family presents. She proposes to Tamilselvan "Selvan", an engineer older by seven years and friend who shares her progressive values and works on transmission towers for the benefit of the people. However, Kayal becomes upset when she receives an anonymous letter; the writer reveals they know her true identity as a female writer using a male pseudonym. Suspecting Selvan, she discovers his regressive nature from his diary and realises she must escape the marriage. Her brother Shankar suggests clearing the Hindi exam and transferring to Calcutta, despite her ideological reservations. Kayal and her friend Alamelu plan to learn Hindi from Suneel, their bank peon. Meanwhile, Selvan grows suspicious of Kayal's secretive behaviour and avoidance. She requests an early exam date from her manager, Ashish Gupta, who arranges it. Kayal and Shankar devise a plan to find someone to impersonate her for the exam. Selvan follows Kayal to the exam centre in Sitrur, far from Valluvanpettai. Kayal smuggles out the question paper, which is taken back to their village for Suneel to answer. After overcoming numerous obstacles, the completed answer sheet reaches the exam hall just in time. Selvan confronts Kayal, questioning her, but she responds boldly, and he leaves, seemingly angry. Kayal hopes this will prompt him to call off the marriage. However, Selvan discovers from his mother that Kayal has seen his diary, where he had expressed his anger and understands of her plan to stop the marriage. He meets Kayal and feigns reform, accepting whatever decision she makes, thus foiling her plan again. Meanwhile, Ranganathan has been trying to reopen the Valluvanpettai Hindi Sabha for two years, seeking revenge for the humiliation he suffered at the hands of Kayal, finally obtains permission and also receives an anonymous letter from Selvan, revealing that Kayal took the Hindi exam for promotion and that her marriage plans are underway. As the wedding preparations progress, Kayal's sister-in-law, Poongothai, suggests abducting the groom. An anonymous letter, supposedly from "Suman", lures the groom to an isolated place, where he is beaten and locked up. Kayal is relieved that the marriage has been stopped, but Selvan unexpectedly reappears, and the proceedings resume. Ranganathan crashes the wedding to announce the reopening of the Hindi Sabha, prompting Kayal to interrupt the ceremony and vow to stop him. She reveals that she took the Hindi exam solely to prevent her marriage. When Selvan claims ignorance about the reason for stopping the marriage and innocently asks for an explanation, Kayal accuses him of being impotent, hoping to provoke his true intentions. Selvan's anger gets the better of him, and he reveals his true
male chauvinistic nature. Kayal retaliates by comparing the imposition of marriage on her to the imposition of Hindi, highlighting the parallels between the two. Meanwhile, the doctor discloses that Raghothaman's stomach issues were misdiagnosed as cancer, and Raghothaman slaps him for the prolonged confusion. Despite his earlier pretenses, Selvan still attempts to portray himself as reformed, but his mother sees through the facade and slaps him, ending the marriage. Later while Kayal sits at a bus stop, an ardent reader named Kamal, inspired by Ka. Pandian's feminist and progressive stories, expresses a desire to meet the author. Kayal reveals herself as Ka. Pandian, finally shedding her anonymity. == Cast ==