Wicked City is the one of the BEST anime that I've seen.

The version I saw was brilliantly dubbed and I think one of the voice
actors is the same one that does the English dub of Happosai.

Anyway, it takes place in a futuristic like world.  There are people
from somewhere called the Black Worls (I think) and they are 
youma like, but more gruesome.  The main character is a guy named 
Takagi or Takashi (Taki for short) and he has to team up
with a Black World operative to protect an important dignitary who
has to sign the peace treaty between the two worlds.  But there are
a couple catches.  The Black Worlder is female, and there are some other
Black Worlders who are out to kill him.  It's slightly
"H", but the "H" part has a reason for being there.

You'll like it.

Foxtrot the Furrryous