Note: This review is not reflective of the manga of this series, which was actually very good.
This is another Manga-turned-Anime where the storyline, character development, and additional story arcs are completely butchered and therefore, the OVA makes absolutely zero sense. Unfortunately, because of this, it makes it hard to give it anything but a negative review. The plot is presented in a disconnected fashion, and without the neccessary background knowledge that is provided in the manga, but not in the OVA, it's very hard to understand just exactly "wtf is going on!?". To further demonstrate this, at the time of my watching, the top rated comment on one of the episodes was "so this anime begins with shower rape and ends with a guy in a kimono riding a go kart".
Zero character development in this OVA makes it very hard to understand each characters motivations. Kai is presented as a control freak and sex addict, and Yuzuru is presented as a doormat with zero braincells, who falls in love with someone who publicly sexually violates her.
The only redeeming factor of this OVA was the animation, and yet even that wasn't that great.
All and all, this OVA was pretty much absolutely terrible, and I wish I could have my hour of my life back that I spent watching it.
I caution anyone who is going to watch this to please have read the manga first, because this OVA simply does not do the manga justice in telling the story.