Yeesh. Such drama. The translation isn't the best, but it's not like I can't fill in the blanks, but I wouldn't apologize for being confused either.
Kaoru as a MC (based on what I've read on MangaDex) irks me, confusing or not. I still can't quite put it into words, but I think it has more to do with how she treats people than her objective suddenly changing.
Yeah, I'm not 100% confident this is it, but I think the reason I can't bring myself to like her (or the MC of 40,000 coins for that matter) is because in the process of jerking back and forth between benevolence and MC-centric justice, or showing off and discretion, she's effectively this monstrous...thing that's wholly selfishly forcing its way through everybody's lives in a way that's just...unpleasant.
Judging from the fact that people seem to like how smart she is (and I agree), I might be alone here, but the way she treats people as pieces to be manipulated and the narrative treats them as means to make her look good makes her kinda unlikable to me in a way most other guile heroes don't.
Some Isekai protagonists might be bland, but these sorts of protagonists are the sort of people I hope I never meet. Which doesn't necessarily make them a bad character, when I look at it like that, but...Hmm. Not sure what else I can say about this.