A triangular love story set in a college and based on an incident in the life of director Jayakumar forms the basis of Unakkaka En Kaathal. Apparently, the incident created a lot of sensation when it happened, and Jayakumar is unable to get it out of his system; hence, the film. He hopes it will impart a message to all, especially college students.
College student Shradda and her cousin Vishnu (Ninaithale Inikkum) hold a torch for each other. Meanwhile, during a problem, Shradda is rescued by Shravan. Her gratitude slowly turns to love. And, the triangle falls into place!