Sixteen-year-old Billie works as a water park lifeguard with her two best friends, but her summer turns upside down when she falls for a charming cyclist.

At 16, Billie is lingering behind in almost everything: in love, in her growth spurt which recently propelled her to almost 6 feet, in having her first period. In a hurry to catch up, she begins her summer as a lifeguard at the water park with her two best friends Rosine and Juliette, and her oh-so-perfect older sister Annette. In this summer in which anything is possible, everything goes wrong when Billie and Annette both fall for Pierre, a talented local racing cyclist. What ensues is a heartbreaking love triangle where Billie must once and for all take her place, shine bright and fight to live the love story she deserves, while protecting the bond with her sister, which will prove fragile, but ultimately indestructible.