Chérif is 15, a rebellious and solitary teenager. Unable to cope, his mother decides to send him to live with his aunt and uncle in Strasbourg, where he must pick up his vocational training to become a builder. It’s his last chance. But very quickly, Chérif feels like he’s suffocating in his new life, while every night, graffiti artists set to work on the walls of the city. A new world opens up to him…