In
Koisuru Boukun, there's a time when the uke have to go trought ''self sacrifice'' but it's not rape or torture... actually you'll see! xD So funny. Anyway the whole manga is amazing.
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Bi no Isu is almost perfectly what you asked for.
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You're my LovePrize in Viewfinder: Some chapters fit PERFECTLY what you want! =D Love it love it love it!!! *-*
Hoshi no Yoru ni Furete : hmmm... not really what you asked for... actually he suffer torture, from the seme, because the seme have... health problems. You'll see. Good anyway, intense. =P
Same thing goes for
Sadistic boy but personality problems.
Tori Maia is one of my favorite author.
Similar thing as above for
Aigan Shounen. The seme have some personality problems and so he tortures the uke but the uke accepts it for the seme's sake. This one is very dark... Wasn't sure I liked it, but it's only personal.
I don't remember about
Mori no Koe or
Yurusareta Uta. You can always try...
I'm sorry if everything's not perfect, but they're all good at least so it can make you wait until you or someone else find more. =)
I think your request is very interesting. I like that too and will search for more. (Viewfinder is gold for that topic, I want more) I'll edit if I find some.
Good reading! =)
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Variety's the very spice of life, That gives it all its flavor. -- William Cowper