Paris and its suburbs. Two stories, four girls, four boys, on one summer day that will change their lives forever.

Set in Paris on a hot summer day, this joyful and funny two-part film follows five young men and five young women where the boys cause trouble for the girls. In the first part, colleagues Milena and Lucie go Sunday swimming in a public pool. The incessant flirtation of lifeguard Jean disrupts their burgeoning friendship. In the second part, Hanne, a young Norwegian student, just wants to have a nice time with her friend Salomé on the national day, but she has to fend off the attention of three men while not upsetting her friend, who has taken a liking to one of the men.