I know this manga is supposed to be really.. really messed up.
The MC isn't the good person we know.
She hooked up with anyone in the bar, and even forced it on someone (Io) who were 'unconscious' when she took her to the hotel.
Still, this is weird...
Somehow..I wonder why
I can't hate MC at all.. Is it really because she's pretty that I can't hate her?
a) She didn't force anything on Io by taking her to the hotel, she just didn't have explicit permission to continue after Io fell asleep
b) she received that permission after the fact
c) until b happened, Masa felt really guilty about it.
That's a pretty good combo of things to successfully have a protagonist do something morally very dubious while getting the audience on board, I think. The framing makes it a moment of human weakness, of someone listening to the devil on her shoulder rather than her sense of morality, rather than a moment of a character victimizing another. The devil on her shoulder clearly had a hunch that she could do this and it be accepted for it, based on what she'd seen of Io so far, and it turned out to be correct.