Ottayan is an action drama based on revenge. Ramesh an orphan is taken in by a poor family, he is an auto-driver. The girl in the family is constantly disturbed by two rich youngsters. Ramesh warns them off. Jilted they kidnap Ramesh's sister and rapes her, his sister stabs Suresh fatally and Suresh strangles her down before dying. Knowing the news Ramesh comes first to the scene. Police seeing Ramesh in the crime scene arrests him.