HarukaxKanae, onthe other hand... They are shown has having interacted before, in a way that should have sticked with Kanae, How is it that she didn't remember Haruka as "oh, is it that girl from the vending machine ? We even ended up in the same class ?"
Note that this isn't the actual entrance exam, but a practice test held in eight grade. Haruka and Kanae weren't necessarily in the same class during their first year of high school, so there may have been two years between this and their next interaction. Seems like a long enough time to forget the face of a person you talked with casually for a few minutes.
I think it’s plausible Kanae doesn’t remember. Before Kanae connected with her classmates she always seemed like she was an outsider peering into the world of high school girls. She didn’t get how her classmates would act the way they would and thought school was only about studying and getting good grades. This recent mininchapter even finishes with her saying that she felt she would 100% get in because of her ability, discounting the serendipity and romanticism of odds/chance.
Haruka on the other hand always seems to notice the serendipity and small moments, I can see her remembering the vending machine moment and Kanae.