A remake of the hugely successful Malayalam film Kadha Parayumbol, Billu (formerly "Billu Barber") is the story of a small town man, Billu (Irrfan Khan) who mentions to his family that he was once a friend of superstar; Sahir Khan (Shahrukh Khan). Then everything changes when Sahir Khan makes an appearance to film a movie in the town. Rumors spread that Billu is Sahir's close friends, and he becomes a celebrity virtually overnight. The trouble begins when townsfolk want to meet with Sahir but Billu is unable to contact him.
In a gritty and alternate 1985 the glory days of costumed vigilantes have been brought to a close by a government crackdown, but after one of the masked veterans is brutally murdered an investigation into the killer is initiated.
This psychedelic tour of life after death is seen entirely from the point of view of Oscar (Nathaniel Brown), a young American drug dealer and addict living in Tokyo with his prostitute sister, Linda (Paz de la Huerta).