My fucking god the sudden introduction of shit disturber characters is the worst trope/ plot device in the history of romance manga.
I understand the ooooh she's going to be the driving force that makes yuzu realize her own feeling but that doesn't make it any less of a shit tool.
I feel like especially shit like this happens too much in romcom type romances where the author can't seem to find a way to push their characters without using a melodrama drama genre trope.
Honestly this, when I saw her appear in Chap 13 I immediately was like oh no, I'm not going to like this development and then Chap 14 really drove that home...
Also throughout this manga, it gave the vibe of "homophobia doesn't exist/super normal to date girls" which is fine, it happens a lot in Yuri and at least it means you can forgo the angsty "but we're both girls!!" route - though now with this new character being like "oh I have a chance cause you also like girls!" it really is now having to address that to date girls means you are part of a minority, though maybe this will be ignored by the classic "I don't see her as a girl, I see her as Yuzu" which I really hate as a trope.
To me its lazy writing, Yuzu has been projecting "friend only" signs throughout the whole manga so far, I think it would've been more interesting for Minami to confess and for Yuzu to deal with that, whenever she does something too touchy she would become hyper aware and awkward, her thinking over what she thinks their friendship is, maybe the confession triggering something to make her think about Minami in a romantic way and then slowly developing feelings.
But introducing this meddling student who's going to be very blatant in how she feels, just for a an easy solution of "Yuzu will feel jealous and then realise her feelings" is so boring...