Irma la Douce (1963)

Naive, by the book, French police officer Nester Patou, is transferred to the Red Light district. Upon witnessing what must be a brothel, he calls the station and organizes a raid, transporting all the 'ladies' to the jail. This unfortunately disrupts the well organized system of the police and the Pimps union. Not to mention inadvertently netting his station superior at the brothel. Fired, he goes to a bar to drink, is befriended by Irma, beats up her pimp, and finds he is now Irma's new pimp. Nester does not like the thought of his girl seeing other men, so comes up with a plan.