To cheer Sophie up, Julien gives her a small tin box, a gift from his fatally ill mother.

As Julien wants the box back at the moment he gave it to her, Sophie demands proof of how important it is to him.

Between the son of wealthy Belgian parents and the daughter of poor Polish immigrants a lasting friendship develops.

On the night of Julien's tenth wedding anniversary, Sophie sends a message to him, indicating that the game is back on.

The other ending has the now aged Julien and Sophie spending time together in a garden and carrying on playing their game with milder dares.

Several distinct versions are used, including the Édith Piaf original, covers by Donna Summer, Louis Armstrong, the Brazilian A cappella group Trio Esperança, and French pop artist Zazie, as well as a handful of instrumental cuts.

Additionally, Cotillard was subsequently cast in Inception, a science-fiction thriller where Piaf's song, "Non, je ne regrette rien" plays a key role.

The critical consensus states that "The romantic leads are too obnoxious and self-centered to generate interest or sympathy.

"[11] Conversely, James Berardinelli of Reelviews.net awarded the film three out of four stars and praised Canet and Cotillard's performances, opining that they "make one of the most delightful screen couples in recent years.