In Thappana, Mammootty essays the character of a person who fights for justice all the time and in the process gets involved in other people's problems. Monai fights for others seeking justice and ends up getting arrested. All the main jails are like home for him and police are his friends. He is an artist and is acknowledged as best artist of the prison three times.
Monai, who loved Mary kutty (Charmi) while he was a teenager happens to meet her again as an adult on one of the days of his release from the prison. Monai spots Mallika who too got released from the women's cell. Monai views it as his responsibility to escort her home. She refuses to utter a word to him during the journey back to her home. Monai soon realises that Mary kutty's life is a complicated one. Mammooty plays Monai and Charmi essays the role of Mallika. Screenplay is penned by Sindhuraj.
The shooting for Thappana has begun at Ernakualm and will later be shifted to Palakkad. Vidya Sagar has scored the music for the film while the lyrics is penned by Anil Panachooran, Santhosh Varma and Murukan Kattakada. The rest of the star cast for Thapanna includes Murali Gopi, Lakshmi Priya, Vijaya Kumari and others. The film will be produced by Milan Jaleel under the banner of Galaxy films.