While most people fall in love and then move in together, a nerdy musician manages to get it backwards in this French comedy. David (Emmanuel Mouret) is a French Horn player who has come to Paris in search of a job playing professionally with an orchestra. David is socially inept and painfully shy around women, so he's quite surprised when, while looking for a flat, he meets Anne (Frederique Bel), a beautiful but scatterbrained gal who informs him she knows someone who is looking for a roommate. It's a while before Anne gets around to telling David that she's the one in need of a roommate, and when she asks him if he'd like to start splitting the rent at her place, he agrees. While Anne would appear to be infatuated with David, he's too nervous to do anything about it at first, and by the time he's worked up the courage to make a move, Anne informs him she has a new boyfriend. Determined to beat Anne at her own game, David tells her he's won the heart of nineteen-year-old Julia (Fanny Valette), though the truth is he's been hired to give the awkward girl French horn lessons by her social climbing mother (Ariane Ascaride). However, David's efforts to one-up Anne hit a snag when he learns the truth about her new beau.