The beginning (like, the first hour), was really shallow. I hated all the characters: the perfect schoolmom, the perfect husband, the annoying little pink brat, and the blue weakling. The extremely cliche fallintheriverchangescompletelyafterwards was boring as shit. The change in both characters was horribly predictable, yet still entertaining.
I found the characters of the kids rather well done psychologically, actually, despite their shallow first appearance (the mom is boring). The focus isn't so much on that though, which is a shame, because there could be a lot to be said about this kind of secret and how they live it. We had a glance at that, but it should have been more developped. The movie has a lot of hidden messages and little things that make it easier to understand - and better. For instance, the little song (the charm to prevent the girl from turning into a wolf), the dress the mother sewed so the girl felt more comfortable in class, and that scarf the boy had always been wearing while he was accepting himself as a human, then drops at the end as a wolf when he decides to live in the forest (while his sister is still wearing the same dress, which has the exact opposite meaning).
The animation is mind-blowingly good, and the music is nice. If there was a lesson to remember from this (as usual in this kind of movies), I think it would be that one is free to choose their own path, regardless of their origins and secrets. To be honest the movie left me in a rather meditative state (though that's mostly the case when I watch anime and movies that are actually deep), but it's good. Definitely worth it, and a rather pleasant surprise, especially after the disappointing beginning.