Kamali, a graduate, lives with her sister Malliga and brother-in-law Shekar in Kotagiri, and is searching for a job. While visiting Madras, her purse is stolen and she fears she has lost her academic credentials. Suriya, an orphaned, carefree man who works in Jaipur, finds the purse and sends it back to her, and a love develops through letters. They agree to love each other without meeting, as she sews and sends a gift pack containing a lotus embroidered woollen sweater for him to wear when they meet for real. Suriya is soon transferred to Madras and stays with Siva, his new colleague. Kamali too comes to Madras to find a job and stays with her friend Jensi. Neya, Suriya's new boss, is immediately smitten by him, but her repeated attempts in gaining his love and affections fails as he is staunch about his love for Kamali. In the meantime, Suriya and Kamali run over upon each other without knowing who they really were, resulting in negative perception and misunderstanding. Refusing a job offer which would move her to Singapore, making it difficult for her to find Suriya, Kamali moves back to her home in despair.

Unable to withstand the advances of Neya, Suriya quits his job and gets sheltered by his friend Paneer, an auto rickshaw driver, who arranges him an auto rickshaw to drive for a living. Jeeva, a wealthy businessman, expresses his interest in marrying Kamali to Shekar, but Kamali excuses herself to consider her as prospective bride when she meets Jeeva in private and shares her unflinching love for Suriya, who even allows her to meet him for one last time. Shekar, who initially dissuades Kamali's love finally gives in and allows her to go to Madras half-heartedly. Upon arriving in Madras, which is experiencing severe monsoon, Kamali finds out that Jensi and the other hostel mates are not in town. Pinning hopes, she boards the Suriya's auto rickshaw, without knowing that it is him, and searches for him desperately. At the end of the day, both of them get refreshed at his place, where he dons the sweater gifted by her, covering it with his uniform. As Kamali plans to head home, depressed, Suriya helps her to board the Nilgiri Express. As the train departs, Suriya removes his shirt after tea spills over it. Kamali notices the sweater, deboards the train and the pair finally unite, as Paneer and Jensi look on and rejoice.