Leon (Claude Melki) is the naíve tailor who believes men are coming to see his trollop sister Marie (Bernadette Lafont) to have their palms read. Her boyfriend Maxime (Jean-Pierre Marielle) acts as her pimp. Marie saves Arlette (Chantal Goya) from suicide and the shy Leon falls for the young provincial girl. Arlette is recruited by Maxime, and Leon learns the truth about his sister. He sends away Arlette's potential customers with a variety of ruses and excuses, eventually hoping to win the girl's heart himself, but Arlette eventually returns to the country when she ponders her life as a Parisian prostitute.