I agree with the general opinion in this forum that seems to be “making mai the victim in this is gross and the obsessive black haired lackey victim blaming the MC is abhorrent”. No matter how enticing the yuri may seem this development is a poor reflection of the author in every way for what’s supposed to be considered a serious story beat.
That said it’s not so surprising this is the path the story has taken, it’s clear the author takes your assumption of Mai “meaning well” or “being a good person” for granted cause duh, it’s a romcom, why else would she even be the main love interest. This is obviously not reflective of real life since anyone who does something to you against your will can and should be suspected of ill intent regardless of the stated purpose, but in a story these things are absolute facts and for what I assume to be convenience’s sake the story takes the path of least resistance, make the main character regret their justified and reasonable actions, have a secondary character scold or otherwise motivate them to do what their guilt may already be telling them to, manufacture some reconciliation where both parties restore the status quo while barely (or not at all) establishing boundaries or demonstrating lessons learned, and lastly, framing this entire situation as character growth for all involved when the only real change is how much you realize the author isn’t talking this seriously.
There is something to be said of black haired lackey’s handling of the situation and how in any normal scenario the right call would be to distance yourself immediately from these freaks but without them any chance at plot progression evaporates due to the MC’s impossibility brittle backbone