This is a seriously underrated anime.
Calling it a hentai is not correct, you should watch it even though it has that tag. It is just a shame it has only 4 episodes. I want a second season.
Art: 10/10
Well not really. But for what it is its art is as good as it gets.
Story: 10/10
Very engaging and stimulating story. I won't spoil it but it is full of twists.
Voice acting: 10/10
The very best of sounds can be heard from your speakers when you watch this anime. It is very very realistic sound, trust me on this, I am pro. ;)
But seriously now. This anime is actually great. I'm not a fan of hentai normally but this is good stuff.