A mute John Doe with the mental capacity of a five-year-old is released from a mental hospital when the state cannot afford his treatment. He begins living on the streets and taking direction from whomever he comes across. While making a biopic about Billy the Kid, the Producer is incensed that method actor Sir Tom Bingsley refuses to leave his trailer. Since this costs the film time and money, the Producer resorts to using a stand-in. The Producer comes across the John Doe selling oranges on the street and hires him due to the striking resemblance to Bingsley. Meanwhile, Lenny is a struggling publicist who has not been able to maintain one client since moving to L.A. and bribes his way onto studio lots to look for talent. Lenny sees John Doe filming the biopic and misunderstands his name to be "Latte Pronto" due to the Producer demanding coffee. After Bingsley dies in a misguided method acting technique of hanging himself, "Billy the Kid" is forced to continue filming with Pronto as the star. Although hindered by Pronto's lack of acting talent and his continued looks directly into camera, his co-stars Christiana Dior and Chad Luxt are inspired by the supposed avant-garde performance and emulate his acting style. Lenny plans to propel Latte Pronto into stardom by getting him an agent and representation. Pronto is befriended by Luxt taking him to wild parties and showing him the Hollywood lifestyle. Simultaneously, Dior becomes infatuated with Pronto due to his sincerity. Dior convinces Pronto to marry her and they adopt several children, increasing their profiles in the media. "Billy the Kid" is a massive success, with critics praising Pronto's performance of breaking the fourth wall by looking into camera. At the after party, Lenny asks Pronto to confirm they will never end their business relationship. When Pronto cannot respond to Lenny's request, a security guard tries to escort Lenny out for disrupting the party. A fight breaks out with Pronto being blamed and sued by the security guard. The Agent asks Pronto to lay low from the media, while informing him of an offer to star in "Mosquito Boy" directed by Lex Tanner. While filming "Mosquito Boy", Pronto is taken out by Luxt for a night on the town which ends with the two in jail after assaulting a paparazzo. Even though Luxt was the aggressor, Pronto is blamed in the media. This further strains his relationship with his representation. While filming "Mosquito Boy", Pronto is injured and a stand-in is used for the majority of the movie. Lenny promises to publicize the film into a big hit regardless. The movie is a colossal failure at the box office and Pronto's representation leaves him. Dior is frustrated with her husband's failing stardom and controversies, so she divorces him, takes the children, and begins dating Luxt. Pronto is forced to move in with Lenny and the two bond over their mutual hardships. Lenny has a heart attack following his consumption of dozens of energy drinks. Pronto stays by his hospital bedside but leaves the room when a fan wants a selfie. Due to a mix-up with a nurse and a deceased patient, Pronto believes Lenny died while Lenny believes Pronto abandoned him. Lenny resolves to become a better person and successful publicist. Meanwhile, Pronto goes back to living on the street. Pronto befriends a homeless man named Dagger and saves his life, gaining media acclaim and is awarded the Key to the City by the Mayor of Los Angeles. The Mayor privately encourages Pronto to run for office on an anti-corporate platform since his acting career is over. The rich and powerful Cote brothers have Pronto kidnapped to discourage his political career. Ed Cote threatens his life should he oppose any of the Cotes' business interests. In return for abandoning politics, Ed Cote arranges for Latte to get his representation back (minus Lenny) and another chance at a movie career. Disillusioned with filmmaking, Pronto abandons his representation and wanders the streets aimlessly. Lenny sees Pronto and chases after him. Lenny apologizes for using his friend as a meal ticket and tells Pronto he loves him. Saying his first words, Pronto responds, "I love you too." The two leave to get dinner together and catch up.