Gaspard (Melvil Poupaud) is a young mathematician/musician on holiday by the seaside in Dinard, a small Breton seaside resort, before starting a new job. The film covers roughly three weeks in his life and introduces us to the trio of women he encounters during that time. First is Margot (Amanda Langlet), a cheerful waitress who enjoys spending time with Gaspard, but isn't interested in more than a friendship. Solene (Gwenaëlle Simon) is more affectionate and sensual - she's willing to have a relationship with Gaspard if he will commit to only her. Then there's Lena (Aurelia Nolin), Gaspard's longtime semi-girlfriend whose ambiguous romantic attitude towards him keeps him in a state of permanent consternation. Gaspard awaits Lena, who does not immediately arrive. Only a short while after this, he crosses paths with Margot, and they develop a strong friendship; Gaspard also has a fling with Solène, Margot's adventure-seeking friend. Lena eventually does turn up, and by this time, Gaspard has become attached to all three women. As the summer wears on, Gaspard finds himself increasingly torn between the three women, finding each the most appealing when he's with her, and recognizing that the day is fast approaching when he will have to choose.