A lot of people who read the source material were really excited for this OVA. After taking a look at the promo pic I thought: So far so good.
Sadly this all started going downhill when they released the preview and after watching the first episode of this OVA I can tell you that I'm thoroughly disappointed. Getting straight to the point: The boobs are way too big. Nothing kills my boner more than watching big tiddies. The way they adapted this doujin is punch in the face of every lolicon. I simply don't understand why they had to ruin this great doujin series like that. The animation itself is okay for a hentai, but the character design is just awful compared to the source material. The succubus in the first episode isn't cute or petite, she looks like a fucking hag. I'm also a bit confused by the sounds. Overall they're done fairly well, but the awkward moaning of the MC is, well, awkward. Also, don't look for a decent story or a plot at all, but that's pretty much expected of any hentai.
Anyway, I do not recommend this series to any intellectual (lolicon). If you liked the source material do NOT watch this, because it's an insult to a great doujin series. A pleb who likes JK might be pleasantly surprised watching this though.