The Raffin Commissioner investigates the murder of an industrialist and it soon becomes apparent that the activities of the relatives of the deceased all revolve around the Folies-Bergere.

The Count De Rochambeau wants to marry Mireille but she likes Etienne. The sister of Etienne, nicknamed "the girl with buttons" schemed with a friend to pose as a Russian princess to seduce the count and allow the marriage of his brother with Mireille.

A young woman has been run over by the car of Carlos, a brilliant embassy attaché. Feeling sorry for her, Carlos drives her to his place and decides to take her in. The young lady accepts his offer but refuses to tell Carlos her name, wanting to be called Miss Pigalle, after the Paris district where she was born. It does not take long before Yvonne (Miss Pigalle's true name) and Carlos fall in love. Life is like a dream and, when Yvonne gets pregnant, their happiness is at their peak. Unfortunately, a revolution breaks out and Carlos returns to his country in secret. Feeling forsaken and at a loss, Yvonne, who is now penniless, has no other solution but prostitute herself.

Michel Lenoir, a successful interior designer, has reached the middle of his life without ever getting married. A bit blue over it he dreams one night of a beautiful young woman. When he wakes up he is persuaded that this is the girl meant for him. He can't help thinking about her, talking about her, drawing her figure, her face, her eyes on paper. He even gives her a name: Sylviane. Later on, as he is holidaying in Portugal, he notices a charming girl swimming in the pool he is in. No doubt about it : he has found Sylviane. He follows her, talks to her, woos her and they are soon married. However, back in Paris, Michel realizes that Betty, an articulate sports writer, is not the idealized woman his brain had conceived. Things go awry and the couple is about to separate when well-meaning friends intervene and open up Michel's eyes : he must base his love story on everyday reality not on idle dreaming.