Luis Costa (Alain Chabat) is living a charmed life: he is a successful perfume designer, known around the office as "Le Nez" (the nose), he is a handsome forty-something, and above all, he's carefree and single. He dates whomever he pleases and happily lives alone.
Luis' happy existence is threatened when his strongwilled mother and five equally overbearing sisters decide it's time for him to marry. They are sick of doing his laundry, cooking his meals and waiting on him hand and foot, so they set him up on a seemingly neverending series of blind dates with all of the single women they know (and even some that they don't -- found via the internet).
After a month of exhausting bad dates, and too afraid to take on his family, Luis hatches a hare-brained scheme: he will find the "perfect woman," pay her to pose as his fiancee and charm his family, but then jilt him at the altar on their wedding day. That way, his family will feel sorry for him and never mention marriage to him ever again. Emmanuelle (Charlotte Gainsbourg), his best friend's sister, has just moved to Paris and is looking for a quick way to earn some cash. It seems like a win-win situation, but the best-laid plans of single men can go horribly and hilariously wrong.