Surprisingly this short OVA was really interesting. So interesting that I didn't notice each episode was 40 minutes long until the last episode.
Story
I guess you could say the story is pretty typical. A group of people exterminating demons to keep the town at peace [or because it's their job], but it has a more, how should I say this, natural feel to it. Most of the time an anime with this kind of story tends to be a little too supernatural. Sometimes even making totally impossible things seem possible.
Art
The animation was beautiful the whole way through. It was really detailed, yet sometimes so detailed it was disgusting. I just wanted to skip over some of those deformed faces. There is also a problem with some scenes being too dark. I know this is supposed to be horror, but it made it hard to see what was going on.
Sound
I didn't pay too much attention to this, but the reason may be that there was barely any BGM. It sounded as natural as possible when in the city or a bar. The only time there was some music was during an action scene to make it more exciting.
Character
The main characters made this fun to watch, but there wasn't much to them. You were never told why Enma has to destroy these demons, how he met Yukihime or how long they have know each other, and what Kapaeru's true form is. All of the character development was spent on the minor characters. Which in this case is important to better understand the situation they face.
Enjoyment
The comedic scenes created by Enma and his group were always entertaining. There were some nice fights as well, but they never lasted any longer than maybe 3 minutes. Some scenes, on the other hand, felt like they were longer than they should be. I'm sure each episode could have been 30 minutes or a little less if they wanted to make this more enjoyable.
Overall
In the end this OVA receives an 8. There isn't really anything else I can say except if you have time and this interests you then give it a shot. I enjoyed it and maybe you will too.