The film opens with the discovery of a corpse of a teenage girl who was brutally murdered.
Arun Kumar (Vishnu Vishal) is an aspiring filmmaker who wants to make a movie on psychopaths. After being rejected many times and due to pressure from his family, he decides to give up his dreams and become a sub-inspector with the help of his brother-in-law Doss (Ramdoss), a police officer himself. He moves to Chennai to stay with his sister Kokila (Vinodhini Vaidyanathan), Doss, and their daughter Ammu (Abhirami). Ammu gets into trouble when she makes Arun sign like her father in her report card. Her class teacher figures this out and thinks she signed it herself. He meets and befriends Ammu’s teacher Viji (Amala Paul) and her niece Kayal (Baby Monica).