That's not something I'd normally complain about, but what ruined this manga for me was the excessive sex. Generally, I didn't like it. The description sounded interesting, with a complex plot...well, it's not. Most of them are overdramatic and don't convince you to care, so it didn't keep my attention. And I didn't like the art much, too.
The first story is disgusting. How can Rei have sex with the doctor right after he'd been doing it with an old men?! Gross. It had a good plot, and it's been wasted with meaningless sex.
The second story is better, though. The plot is different from everything I've seen before, and I give it credits because I loved it. But again, too much sex...and that takes out the time that should've been spent with a better developement.
The third one was cute too. But nothing much too it, just cute.
Fourth one is also disgusting. I like sadistic semes (actually, they're exactly my tipe), but Naomi is a little too much, and Honoka is creepy. Despite all this, it is really sad and deep. Had potential, but unfortunatelly, it was wasted.
And just to surprise me, that last one was also really, really sweet and didn't disgust me at all. I normally don't like gentle semes, but Kagami was quite a catch =P And Jin was really cute too! I liked it a lot!