I watched this anime a couple of years ago when it was aired here in Australia under the title 'Shinzo'.
I really liked this anime. I found the story line flowed well and didn’t drag on like some other ones do.
The main character Yakumo reminds me a lot of Relina from Gundam Wing. She tends to overdo it a bit on the ‘all must be peaceful’ ness but not too bad.
The other characters are good to, I think that their animation becomes a lot better once they transform though. The look a bit comical in their usual form.
I think the series is focused more at the 8-14 age group but I am 20 and I liked it :)
I do find it a bit strange that there seems to be nothing much about it on the internet and that most people have never even herd of it.