Jean is a naïve and not a very stand up for himself kind of guy. Then he meets Irene, who survives off of rich older men, very rich older men. This woman has probably never read “The Female Eunuch”. If she has, she probably thought it was quaint. Jean falls for Irene the first time he sees her. Audrey Tautou looks stunning no matter what outfit she is wearing. Irene initially pursues Jean thinking that he is a very rich sophisticate. He’s actually a penniless ( euroless ) bartender / waiter. By accident, Jean falls into the same lifestyle as Irene, who now coaches him to get ever more riches from whatever woman he romances. He becomes a very smooth talker and shrewd. Eventually when Irene hits a low point in her life, she realizes Jean is the only one willing to help her, unlike the rich but shallow men she has been seducing. Their romance seems implausible, but it all ends well.
Suggestion : If you usually turn on subtitles, turn them off for this movie. This French film already has English subtitles with excellent translations. The subtitles that are turned on are 2 to 3 minutes behind the action, and their translations of the French are terrible.