In the 1930s, in a village in Gironde, Guillou, a young boy in need of affection, nicknamed the Sagouin, unhappy and in need of affection, leads a life of anguish and sadness in a sinister castle. He exasperates his mother who sees in him only the hated reflection of a husband she only married to become a baroness. Thanks to the kindness of the village teacher, Guillou glimpses for a moment the existence of another world, of gentleness and tenderness.