I saw this movie a year ago and I had to regard it as one of my favorites, if not the best. Though some people think that  the ending in which the director plays one last prank inserts unnecessory ambiguity the two main characters' fate.

The story revolves around Julien (Guillaume Canet) and Sophie (Marion Cotillard), whose bizarre friendship has been ongoing since childhood. It was then that the pair developed a game involving dares, initiated by whichever of the two is holding onto a metallic toy. As they grow up, the dares escalate - for example Julien dares Sophie to attend an important exam wearing her underwear over her clothes - but the obvious attraction between the two has seemingly been ignored in favor of further pranking hijinks.Despite the protests of everyone around them, the pair continue to approach everything the way they did as kids; even something serious, like a wedding ceremony, is fair game for one of their outrageous dares.

In my opinion, they are deeply in love with each other,in a cuel way. I was moved by their determination to prove that they are courageous. They dare to sacrifice other people's feelings and their own marriages to keep promises for 20 years. The free and deep love are demonstrated by their seemingly contradictory actions.I wanna say all these have impressed me a lot.