The story of Action Hero Biju revolves around certain interesting episodes in the life of a young police officer, his personal and professional life. Nivin Pauly plays the titular role, Sub Inspector Biju Paulose, an officer in a Janamaithri Police Station. The situations take the story forward. Action Hero Biju is a realistic portrayal of a cops life, in contrast to the macho appearance seen usually in action movies.

When Madhav and Jerrin, who lived together till then, bought two adjacent villas, and started living with their family, they never thought that their friendship will be affected in any ways.