That’s... not NTR... so far the hero didn’t actually get together with a single one of these manipulative women and MC is the “scum who wishes to protect his pure friend”, aka the guy who saved the mc’s life even though they’re supposed to be rivals where only one can survive
(I left no spoiler tags on purpose so anyone who’s checking this out knows the manga is misnamed and not just avoid it, and let’s be honest, not much to be spoiled here tbh)
I took a quick glance at the raws, and from what I could tell the manga itself isn't very far ahead of the translated stuff. I hope it keeps going though. This stuff is a gold.
Explaining the obviously here, don't mind me: Since people commonly self insert themselves into stories, especially ero-mangas, it's ok for the MC to NTR anyone they want, but it's not ok for anyone to NTR him(you). Unless you are into that.
I mean he is technically not an NTR as isn't in a relationship with anyone nor has he slept with anyone that his buddy has been in a relationship with yet.
trash mc doesnt want his friend to be tricked by anyone so to make sure every girl they meet isnt tricking him he rapes them. sometimes he rapes a terrible person sometimes he rapes an innocent girl. if thats you M.O. then give it a read, if thats not then its trash