Vishnu, an engineering student who finished the course with many back papers, is our hero. He is someone who is good with practical stuff in coding but does not have the skill to clear the exams. His relationship with his classmate Shilpa ended due to his indecisiveness about his career, and at one point, it led to a situation where Shilpa’s father, Chacko, humiliated Vishnu. The decision of Vishnu to give it back to Chacko from his capacity and what all happens in that revenge tactic is what we see in I am Kathalan.