Are you all stupid??
S** is not a legally binding contract. You can retract consent given at any time. If your partner continues after you have REPEATEDLY sad "no" and "stop" then it's r@pe. Also what does it matter if "she knew what she was getting into".. Then it makes it okay? I see nowhere where it indicated she'd be treated very roughly. Nor is it on her for thinking she'd be comfortable with that and later deciding she wasnt. You don't have to carry on with something that makes you comfortable just because you previously thought you'd be okay with it.
"she should have hit or pushed her away if she wasnt okay with it" Have you all never heard of the flight or fight response? It's also very common in r@pe victims. Just because she froze doesn't mean she was okay with it.
I'm hoping the author/artist doesn't just brush aside what happened as "fine because she liked it" which i see so often in manga/manwa which is frankly just victim blaming behaviour. Either way this manwa sucks and I'm dropping it, it leaves a bad taste in my mouth.