This is probably the first series i've come across that actually handled these types of subjects in a realistic and really heart-gripping way.
The character development throughout the whole series is actually one of the best i've seen.
I found myself hurting with the characters, but not to the point where it just felt horrible and overwhelming. The whole story is very engaging.
The ending is a bit random (as with many yaoi mangas.), which is one of the few things I think could have been better. I don't want to publish any spoilers so I'll just let you see for yourselves.
But it's not anything that really affects the overall image.
The artwork is actually pretty good, but it's far from the best i've seen. Plus It's not my favorit style. Wich is why it only gets a 6.
I wouldn't quite classify this manga as "mature" since the sex scenes are very "clean" and doesn't really show any real action. Though it does contain a low level of masochism.
Overall I think you might like this manga if you are more into the non-hardcore/mature -style series.
This is my first review so i hope you find it helpful! :)