In a street called Blue in a very poor neighborhood in Paris, Monsieur Ibrahim (Omar Shariff) is an old Muslin Turkish owner of a small market. He becomes friend of the teenager Jewish Moises, tenderly nicknamed Momo (Pierre Boulanger), who lives with his father in a small apartment on the other side of the street. Monsieur Ibrahim gives paternal love and teaches the knowledge of the Koran to the boy, receiving in return love and respect.