Maxime lives in a foster home and sees his father only a few minutes of each day. Partheepan is at the top of his class in French, but whose mother only understands Tamil. There is also Éric, shy and reserved. And finally, Jimmy and Pierre-Christopher, who have never touched a piano in their life. Those five children must complete a huge assignment: in a few months, they will be on stage, performing a musical inspired by Verdi's opera A Masked Ball in front of a huge audience.