Whimsical

I had no recollection of having seen this before when it came out (I've updated the synopsis and other details which were missing) but it still retains its charm and gets the same rating 12 years later. 

Charming

The centre of the story is the relationship between Nai Nai and Billi, which provides us with a way in to come to understand, as Billi does, some of the cultural differences between the individualistic american way and the Chinese social family. From being initially appalled at the lie that is being collectively perpetrated, Billi comes to accept and even embrace it.

The key scene is where she is with her father and uncle at their hotel in Changchun just before the wedding and they explain the difference between living in America and in China is that in America people believe their life belong to themselves, whereas in China people's lives are part of a whole, of a family, of society, and therefore it is the family's duty to carry the emotional burden of the cancer knowledge FOR Nai Nai.

The whole film is an illustration of this point, and it works really well.