Swarnkamal, a gentle man, arrives as the new Sanskrit Professor at a girls’ college. On the first day he locks eyes with the beautiful Chemistry lecturer Phoolrenu and is instantly smitten. But Phoolrenu is a strict disciplinarian who has no time for frivolities like romance. She has been nicknamed ‘carbon dioxide’ by her students due to her strict ways. Swarnkamal on the other hand is an instant hit with his students. His passion for poetry and willingness to flout conventional syllabi soon makes him a favourite of both students and teachers alike. Phoolrenu is the sole exception, as she is very disturbed by the effect his teaching is having on college discipline. Swarnkamal is persistent in his pursuit of her affections though, comparing her to Kalidasa’s Shakuntala at every turn. Phoolrenu too realises that her strict adherence to codes may have stifled her desires and despite her misgivings starts liking Swarnkamal. She even consents to playing Shakuntala opposite Swarnkamal in the college play.
Phoolrenu has a younger brother Ramesh who is engaged to Usha. But Ramesh has promised that he will only marry after his sister’s marriage. Phoolrenu’s reluctance to commit to any marriage proposal presents a peculiar impediment for his romantic desires. When Phoolrenu visits her home in Kashipur during the summer holidays, Swarnkamal also decides to visit her. As the two get closer to each other, Ramesh keeps trying to convince Phoolrenu to accept marriage proposals. When Phoolrenu finally consents, he advertises in the newspaper asking for letters from prospective grooms.
Phoolrenu and Swarnkamal confess their feelings for one another. But Phoolrenu wants him to send a letter as a prospective groom anyway. When Phoolrenu learns that a college teacher has written asking for her hand, she immediately agrees. Unknown to her Swarnkamal had never sent any such letter. The college teacher turns out to be the two-timing Gopal Krishan Chowdhury. Caught in a sticky situation, Ramesh and Phoolrenu concoct a clever plan to avoid the marriage. In the end, Swarnkamal and Phoolrenu are happily married.