Well I didn't quite get what I was working on up and running so going off topic today.
My favorite S&M manga, believe it or not its not hentai. Nana to Kaoru is an echi series about a pervert who is slowly training his girl next door into a masochist. Very few series actually go into training, and watching Nana slowly become more and more a masochist is just delicious.
The series switches publishers half way through thats why there is both
Nana to Kaoru
Nana to Kaoru (Young Animal)
The series starts in Nana to Kaoru and continues in the Young Animal Version