Season 1: Vincent Picard (Guillaume Labbé), a history and geography teacher, is struck by a terrible tragedy: his wife Justine (Émilie Dequenne) dies while giving birth to their daughter. Faced with this unbearable reality, and in order not to sink, he takes refuge entirely in his profession as a teacher, to the great dismay of those around him and of the principal, Mrs. Mine (Florence Pernel).
Each of the six episodes features one of his students: Lucas, made paraplegic after an accident and who can no longer bear the gaze of others; Chloe, who can no longer find the energy to fight against the harsh remarks of some of her classmates about her weight; Juliette, convinced that she is responsible for the death of her mother and who gradually sinks into alcoholism ; Mehdi, a victim of abuse, which he tries to hide; Zoé, who has been living in precarious conditions for several months, which makes her daily life difficult and begins to isolate her; and finally Alex, whom his friends are gradually dragging towards an extreme right-wing ideology.
These six students manage to overcome their difficulties with the help of Vincent, who struggles to find solutions, sometimes leaving the role of teacher to become personally involved in the lives of his students.
Season 2: Alexandra Delage (Julie de Bona), 38 years old, is a high school teacher like one dreams of. She teaches French with brio and runs a theater workshop. Alexandra is naturally empathetic with her students: according to her, to learn well, you have to feel good about yourself. This is why she tries to solve as many of her students' problems as possible, especially those of one of her first year classes, which are particularly acute.