I believe this is what you are looking for my good man.....or woman.
http://dynasty-scans.com/chapters/her_desire#1
Ohshi-! Natsuneko. Been too long since I've seen her stuff.
This story was pretty fucked up, I guess, but now that the bully has made her move "Sachiko" kinda has a lot more power. I wonder if you have to be in those unstable teenage years to be able to take words like "you're worthless" or "you're gonna be stepped on all your life" seriously. To me, this kind of behaviour really says a lot more about the aggressor than the recipient. I just wonder if it's possible the victim would ever get a grip on reality and be able to realize that. Not to say Sachiko's situation isn't terrible/brutal, of course, but the world portrayed doesn't seem so dark yet as to be impossible to recover from.
In the long term, I do feel like it's Yuna's game to lose. She said it herself, after all, that power and money are the forces of the adult world, and she doesn't seem that much to be able to control Sachiko forever. That's why, I would be interested in a sequel, I guess. It'd be great if Sachiko realizes that her sexuality is a power she has over Yuna and manages to turn the tables on her. At the same time, I guess I'm just dumb/hopelessly idealistic 'cause from there I wish it'd proceed into a vanilla ending.