This film is a commentary on the out of control suburbs swallowing the countryside round Tokyo. It uses popular Japanese folklore to put across an anti-development message.
Tanuki are Racoon Dogs, native to Japan and in the film they struggle to stop the destruction of their forest by using their powers of transformation to try to scare away the humans. "Pom poko" refers to the sound Tanuki make to frighten wayfarers by drumming on their stomachs.
The animation is very special, but the many cultural references and long length (just shy of 2 hrs) mean this film requires perseverence.
The film has a kind of "Babe the sheep-pig" narration, which is good, and some funny scenes where the Tanuki try to learn their art and blend in to human society. Imagine Watership Down, but with the rabbits up for a bit of sabotage rather than moving home.
Although it features fluffy forest creatures, they aint Yogi bear (though they look a bit like him when they get happy!). They are quite prepared to wipe out a few construction workers for their cause.
Past english dubs have tried to gloss over some of the more earthy details. Real-life Tanuki are well known in Japan for their large balls, which were translated for the original Disney release to "pouches". These feature quite heavily in the film, ahem, sometimes literally so - as they are used to crush opponents!
The film has quite a serious message, which means the fun side of the Tanuki, which comes out in many scenes, is eclipsed by the sadness that their habitat is being destroyed for ever.
Overall quite interesting if you want to learn about another culture, and great if you are into animation. Perhaps not so good if you want light family entertainment.