I especially liked the continuation of what I know is a Japanese legend, that if one eats the flesh of a mermaid, one can get eternal, unchanging life. I've always like that that was treated more as a curse than as a blessing. There's a manga about that theme, set in the modern day.
I loved the costumes, the flute, the motion of the actors, the over-the-top cackling of the Bad Guy who was obviously born to be just plain Bad. I loved the ambiguity of Seimei's "goodness", and the earnestness of one only really good guy in the story. I really enjoy how it hangs as the first of what really should be a series of movies, and which I believe is a series of Japanese novels. Now, though, I want the books. Not just translated, but written within the vein of how these particular characters interact. I know that an Onmyoji 2 is out, and it's already sub-scripted. I may have to just buy it.
Thank you, incandescens!