This is like the Mirror Universe of Yuri.
Where in our manga universe high school girls are secretly yearning for their female classmates and their desires are often foiled by being mistaken for het yearnings, in this one our poor little het (as far as we know) girl is put upon by a toxic yuri love interest.
Since Chapter 2 is now out, I assume it’s OK to compare this with the web version of the same chapter, in which case the text in the last panel here is very confusing. (I’ll use spoilers just to be safe, though.)
In the web version Kimura says, “Um, I’d rather you just eat it like a normal person” [rather than keep my cookies as a family heirloom.]
Here the line seems to be Hiyama’s from off-panel, as if she realizes how crazy she sounds, “No…er, I just really want to eat your cookies.” But that makes Kimura’s expression rather odd if she’s not the one talking. If I’m right, and this isn’t just a translation glitch, it will be interesting to see if this version methodically ratchets back Hiyama’s yandere aspects.
Maybe I overdid the spoilers. But OrangePekoe’s initial warning post was scary.