Basically really good, really fun, super engaging, can't wait to read the next one. Interesting story & tons of well-rendered details (ronin! demons! water spirits! mage-ogres!(?)!) make it an immediately engaging world/universe, despite being kind of gory at times.
Two complaints, which are basically my complaints about all graphic novels, ever:
1) I always wish the pages & pictures were larger, because the images are so gorgeous but it's often hard to see exactly what's going on in them, and what exactly I'm supposed to be taking away from them, exactly, and
2) All the women in this story are dead, evil, or geisha. So, you know. That's still happening.
But so I'll read the 2nd volume and will be surprised and delighted if it happens to have a strong female character in it. I mean please.
I will also say that I don't know much about the science of creating comic books, but there was a lot happening with the use of color here, and it was really cool.