I am struck with how shoujo-y this manga is, except that both of the girls are doing the forced kissing part, which is something, I guess. But there're ecchi elements too, like how tsundere Yuzu becomes when she's not a blushing virgin, and yuri elements, like the all-girl boarding school stuff that has absolutely no bearing on the dynamics of the characters. It's an interesting experiment, I suppose, but what results is utter incoherence in basic characterization. The story cycles through the tropes so thoughtlessly that the only constant is: Mei being emotionally unavailable, other people forcing themselves and their feelings on Mei, and Mei's personality being indistinguishable from a drooling zombie. She has the lifeless stare down pat.
The problem is that Mei's behavior is wildly inconsistent. She's kind to Yuzu one moment and cruel the next, and there's no reason given for most of such shifts. As readers we're invited to be intrigued by her but not to understand her and never rewarded for liking her. We understand Yuzu marginally better, except for the part that she luuuvvvs Mei and that she's alternately pushy/rapey and quick to tears. It's frustrating that they are supposed to be anchoring the manga.
It's not properly explained why Yuzu falls for Mei, why she she feels for Mei what she does beyond sexual attraction. She knows Mei as well as readers know Mei, which is to say, not at all. They're uninterested in each other except for possibly sex, but they lack chemistry for that, too.
Anyway, what this manga could be is fanservicey with the right kind of internal logic--it certainly has zero aspiration to by anything else--but awkward characterization is too whiplash inducing for even that.
Edit: I LOVE it that comments on this site are 99.9% bullshit but that so many of the comments on this particular stupid freaking manga is so freaking on point.