Rereading the series, and a few mysterious reactions stuck out to me:
1) In chapter 8, when Honda sees Michi pinned under the shelf in the gym storage shed, she does not shout "Michy!" as you'd expect, she shouts Michi's last name, "Kurotori!". She's right back to calling her Michy again the next panel, as she helps Kasumi pick the shelf up. What's up with that? Given that was a reflexive shout in panic compared to everything else, it makes me wonder if her apparent closeness to Michi something that she's forcing to some degree.
2) When Senpai arrives at the nurse's office afterwards, Michi and the possessed Kasumi are behind a curtain, with Honda on the other side. What's she doing out there, separated from the others? And when Senpai tells her to go find the nurse, she's got sweatdrops and seems really nervous. It's just kinda weird. Why was she still hanging out in the nurse's office but not with Michi and Kasumi? Why was she scared of Senpai?
3) In chapter 10, when Aizawa helps Senpai find the sulking Michi in the stairwell, Michi is shocked to see Senpai talking to Aizawa as if she's normal- and I am too, considering this scene has Aizawa floating around (it's even got a "float..." sound effect to emphasize it. And the "weird guy" she threw ink at in the previous chapter's flashback is obviously inhuman as well, given his shape: Does Senpai just think it's totally normal for some people to fly or have wounds that never heal forever on their bodies or have monstrous shapes?
4) In that same conversation, Senpai waves to Michi, who plays dumb and says "maybe it's a ghost then I dunno lol". Senpai laughs it off, who would believe in ghosts at their age? And Aizawa breaths a sigh of relief for some reason. Why was Aizawa relieved? Did she want Senpai to think she's a normal living student? If so, why'd she float in front of her lol.