This documentary tells the story of the female musical trio L.E.J, composed of Lucie, Elisa and Juliette, whose destiny changed one day in August 2015 when they posted a mash-up of summer hits on YouTube. Two singers, a cellist, a clip shot on the seafront of Lacanau that will go around the world with 70 million views. From one day to the next, these three childhood friends are propelled to the forefront of the stage, without having calculated it. How will they manage the demands of their new profession? This film is the story of a success story.