June 1990 in a large provincial town in France. It's the last day of school. The baccalaureate exams are ahead, but who cares. A small group of students joyfully leaves school. Caught up in the general euphoria, Lucas gets it all off his chest: without mincing his words, he lets his nasty philosophy teacher know just exactly what he thinks. His sense of relief is short-lived, because the ghastly Mr. Martineau will be overseeing the resitting of the oral exams. Lucas better start studying!
That same evening at a party, Lucas encounters Clémence, a beautiful young woman. It seems like a case of love at first sight for both of them, but Lucas lets her leave without asking her name. Between lively reviewing sessions and summer escapades with his pals, Lucas sets out to find the beautiful stranger.
But this is just the beginning of Lucas's worries. For he accepts to undertake private philosophy lessons with Mr. Martineau, only to discover that he is the father of a certain beautiful young lady.