@jokerxhisoka She asked him to:
— Change his clothes after sweating a lot.
— Wash his hair everyday
— Check his appearance in the mirror every morning
— Wash his hands after using the toilet and wipe them dry
None of these things are illogical demands or come even close to her asking him to become a different person, she even points out she doesn't care about the guy getting his hair done in a beauty parlor or arguably the other traits that make him popular. If MC's personality is defined by being a smelly and dirty fuck then that's definitely something he should change because it's unhealthy, or just give up on having a relationship with a normal woman and find someone as sick as he is.
It has been a while since I read this so I can't honestly remember if she made any illogical demands in the past.
@FredFriendly Again, I don't remember much about her illogical demands in previous chapters but from little I can remember, she has been asking him to do pretty minor stuff, though she does wants him to be more "manly" by doing things like being more outspoken and confident, which I don't see as a bad thing.
She is clearly harsh and has her own personal issues she needs to fix, but I don't remember her telling the guy to change in a way that would make him a completely different person or wouldn't be a positive change. That "just be yourself" crap might sound nice but the sad reality is that no one will love a cowardly and introvert human wreck that can't even bother to not smell like shit.
And she knows a lot about that dude because a) he is popular and b) apparently he is the only guy in that fucking school/city that does basic personal hygiene shit, and yet she is spending his time with MC instead of going with that guy. I highly doubt she is with MC just to play with him, this is clealry not that kind of story.