Looking for NTR manga but instead of the asshole stealing the girl i would like to find one were the good guy steals the girl away from the asshole. Does such a hentai manga exist?

I love proving Rule 34 so why not. You would be looking for the category Netori which can encapsulate that but the tagging community apparently doesn´t know what it means as it leads to a string of NTR with both tags applied 🤢 . Sweet Days (TAKASUGI Kou) fits and i brought it before due to a base competence level. I still view it as a failure and also had to set the tag myself. Now you know and knowing is half the battle!

I also read EU/US comics and am a librarian.
Manga-Masters, My ANN-Lists + Imdb

Search "Netori".

For Anime u could watch the hills have size...lol