This is something I really liked that breaks every rule of what I normally like for NTR.
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(this is part 1 it has a part 2 that concludes it)
It's blackmail and rape. But the logic around it works for me. The girl beats up the bully, so the bully makes a fake website to blackmail the girl so that he will get her BFs parent fired. While still flimsy it has some logic to it in that going to the police wouldn't immediately solve the issue. The girl still a bit stupid could have asked the BF to clarify, which she does later after it was too late. This gets her doing sexual favors for the bully. Later the bully rapes her. But by that time she is decently corrupted already, and it escalates from there.
I think the big thing is the change from where she was at the start, gradually to the whore she becomes. It's not a cum whore right away. It's the contrast between start and finish. Righiouse girl who hates the bully to a prostitute who does whatever he says.
A lot of games will say at the beginning intro or description that the girl is a righteous defender of the weak or something, but never show it and set that up in the game. Just a few scenes to set that up, or to show she cares about the BF before you get into the corruption would help a lot in getting that NTR feel. (A quick sex scene with the MC doesn't do that for me)
Just an exception in how sometimes things I normally hate just come together to be something I like.