The film stars Catherine Deneuve as beautiful young housewife Severine, who cannot reconcile her masochistic fantasies with her marriage to husband Pierre. When her lovestruck friend Henri mentions a secretive high-class brothel run by Madame Anais, Severine pays a visit and eventually begins to work there during the day under the name Belle de Jour. But when one of her clients grows possessive, she must try to go back to her normal life.