The art is good as well as the sound in my opinion. However, the story is always the most important aspect of any anime i watch, and the story or should we say stories in Twelve Kingdoms, annoyed me a lot, and to no end. There were too many pointless diversions, and characters introduced that the viewer can just not care about no matter how much they are forced on us.
What annoyed me most was that the writer obviously overstretched the amount of trouble that Youko has to withstand as queen, to a point where it is no longer reasonable, and you just wish she will sit on the stupid throne with confidence, and simply know what to do with common sense, instead of wasting our lives finding out unnecessary things that just annoy the crap out of the viewer.
Also, i did not like Keiki's attitude throughout the series, i felt he was helpless and completely useless at all points even if he is meant to be the prestigious and noble kirin creature. He was either useless, or he was making Youko the queen he chose in the first place miserable with his silence and lack of actual support.
like i said, the story is always the most important aspect. Left to me, Twelve kingdom's actual interesting, and reasonable story fits into just 12 episodes, thus all the other 30+ episodes can be cut. I kept watching and hoping something more interesting would happen, or the characters will finally move, and use common sense, but they were all slow, and uninteresting in their approach to moving the plot forward. Most importantly, i do not feel there was any actual resolution.
Youko's character may have grown a little, however she did not grow as a queen at all. She did not make any real impact whatsoever.
Thus i find myself asking; why did i just waste 2 days of my life watching this? well the answer is that the beginning was not bad, and the other 11 reasonably interesting episodes, were indeed something to write someone about.
