Pepi, a young independent woman living in Madrid, is filling up her Superman sticker album when she receives an unexpected visit from a policeman who has spotted her marijuana plants from the street. Pepi tries to buy his silence with an offer of anal sex, but the policeman rapes her. This ruins her hopes of selling her virginity for a good amount of money. Thirsty for revenge, Pepi arranges for her friend Bom, a teenage punk singer, and her band, Bomitoni (Bom and Toni), to beat up the policeman. Wearing Madrilenian costumes and singing a ''zarzuela'', Pepi's friends give the man a merciless beating one night. However, the next day Pepi realizes that they had attacked the policeman’s innocent twin brother by mistake.