Based on the last page, I'd say she was either trying to get his attention or just looking to start a more steady relationship. Kind of hard to say, given the lack of evidence, but since they both went to the same school together, it's plausible that she was just as aware of him as he was of her. The rumors of her promiscuity could very well have been simply rumors, but her, shall we say, 'adventurousness' in the bedroom might indicate that there was some truth to them after all, and she only realized later that sleeping around only temporarily satisfied her physical urges, and nothing more.
Well, it's a hentai plot in the end, so who really knows.
Final impression (IMHO) is that Kawazaki made major changes from her middle-school days to college life, inclusive of (to put it politely) becoming sexually adventurous (happens to most of us).
IN-teresting how Nagamori seemed to steer his pals away from her; whether it was because (1) he wasn't sure how she had changed, even if he had heard certain rumors, or (2) perhaps a part of him had some interest in her that, for whatever reason, he didn't act upon in the past.
Seeing that this is a work by Cuvie, a specialist in her own way of "playing russian roulette" with H-stories, perhaps a sequel or continuation story just might clear the air about certain things.
I’m leaning toward option (1). He has enough respect for her not to make comments about her past based off rumors and speculation. From the writing, I don’t think she is looking for a relationship but rather feels comfortable around/with Nagamori to fulfill her sexual needs. The moment he abuses her trust, like becoming possessive, she will end it. The look she gives him on the last page combined with “You’re not gonna ask me who else I’m fucking, are you?” tells me Nagamori was one wrong statement from ending their escapade.
It's either that or that was what caused her last breakup; her Ex-boyfriend may have been too possessive, and that's not what she is looking for. In fact, there may not be anything to the rumors.
It would be funny if the rumors were around to attract this guy's attention like you read in other H-Manga stories, and they just failed in this one.
He didn't even bring it up, it was all her both times why is she so touchy about it? It's as if she feels guilty or something, though he didn't step on that mine and could defuse it, it seems as if there is still a few mines to be careful of. Well he is isn't bad with words at least.
Well, it's a hentai plot in the end, so who really knows.