Wow, shit, pretty damn good read. I actually didn't expect anything, it was a wild ride. I watched the OVA and it's totally different to the manga, in a good way, so if you did the same you should start since the start like I did. Solid romance, lot of sci-fi, lot of blood and a decent plot. It had quite a bit of twist that made the story engaging and a solid ending. So a good story with plenlty of romance, some action, a solid pace and a solid ending. I really recommend a try, it was a pleasant surprise.