Amélie Poulain is a shy young waitress at the Café des Deux Moulins. One evening, upon discovering a box filled with childhood treasures hidden behind a baseboard in her apartment, she decides to find its owner. Moved by the emotion of this man rediscovering his memories forty years later, she sets herself a mission: to dedicate her life to bringing happiness to others.

For one unforgettable evening, the waitress from the Café des Deux Moulins will reclaim her magical power: the ability to make us believe in happiness, impossible encounters, and the beauty of life's little nothings.