After finding and adopting a child, a man gets a job at an all-girls school which doesn't allow families. Once the girls find the baby, they become his forty little mothers. At the same time, the child's true mother searches for him.

Monsieur Jourdain is a dangerous madman : he wants to share his fortune! His relatives do what any sensible fellow on earth would do: they have him committed to a mental hospital. But Jourdain manages to escape and decides to make everybody happy except... his heirs!