Banjo follows a bullied office worker named Peltzer, who is humiliated daily by his fellow colleagues and cheating spouse. Once news about his embarrassing bedroom accident makes it's way around the workplace, Peltzer decides to put up with his torment no longer, and conjures up his childhood imaginary friend "Ronnie" by the use of an Ouija board. Peltzer's world is soon turned upside down, as Ronnie attempts to manipulate him, to exact revenge on his tormenting co-workers in the most gruesome fashion. As Ronnie starts wreaking havoc and ruining Peltzer's life and relationships, Peltzer soon finds that the genie is out of the bottle, and no longer able to control his imaginary friend. In this twisted tale of romance and revenge.