Quote from mizunosaki
There's Ai to Yokubou wa Gakuen de
where boys are training to be sex workers and hosts.... I like the art quite a bit and despite the story premise this is not just hard p0rn with no plot... This one has story and romance as well. Highly recommended.
This one is not SM perse, but there's Oshioki Gakuen
that tells a story of an unreal, perverse teacher and highschool. This one is just p0rn
For a non-yaoi one, I think there's Nana to Kaoru
that somehow 'teaches' about SM. It's ecchi though.
Thanks~ Actually, I've read Oshioki Gakuen. It's interesting, but it's too weird o.o
(and like you said, way too unreal ._.)