Why they haven't released this movie in the UK, I don't know. I ordered my copy from Amazon.de (German version, but does have an English soundtrack, and the interviews are in English with German subtitles). It is lovely.
Okay, so this is perhaps not the most profound movie ever made, but it has a good heart, says some true things, and is great fun. The acting is good, not just from the leads (there is a particularly touching scene from Auntie-ji near the beginning) and it is well shot. I was debating whether it really deserved 5 stars, but it would feel churlish not to give them.