30 WILD EPIC Steamy EXCAPADES COMPILATION’s.
And the girl is just a regular friend that finds out how exciting this strange fetish is!
What hooked my girlfriend to this manga was how the characters acted though. Because the male wasn't the usual overpowering asshole, the female wasn't the Pain Slut that many hentai churn out. They were two normal (and very nervous) teens, who just happened to trust each other enough (secretly love each other, though they don't know what the other thinks) to do these SM acts.
My girlfriend and I spent a lot of time reading the manga together. Both of us naked, with her on my lap and a laptop in front of us.