Pizza is an Indian horror film series. Each film starts with a fresh story unrelated with the preceding film's story. However, the theme and the pace remains the same.
Michael Karthikeyan (Vijay Sethupathi) is a pizza delivery boy who lives with his girlfriend Anu (Remya Nambeesan). She is an aspiring novelist and is researching for writing a horror story, whereas Michael does not believe in supernatural powers, but is afraid of anything supernatural. Anu, keeps telling him that he would soon realize the presence of supernatural beings. At first, Michael is confused and scared, and his fears are confirmed when he comes to know his boss, i.e., the Pizza restaurant owner Shanmugam's (Aadukalam Naren) daughter is possessed by a spirit. Meanwhile, Anu becomes pregnant, and after a brief altercation, Michael and Anu get covertly married. One particular day, Michael goes out to deliver a pizza to a customer and returns to the restaurant in a state of shock while covered in blood; he is apparently injured, keeps constantly muttering Anu's name, and seems to be worried about her. When his boss questions him, Michael explains that he had been to deliver a pizza to a customer named Smitha (Pooja Ramachandran) in a bungalow and recounts the events that happened at the bungalow.
The protagonist on a probe to solve a series of murders that take place exactly where he delivers food.