Every chapter is just more and more evidence that Shou's group really sucks. I mean you could say that their energy levels are totally different and they don't vibe, but man are they pushy. They are not accommodating in the least.
So! I just re-read from 15.1 on, paying particular attention to that group, and found more evidence that Aoikani really thinks about the characterization and personality even of these unnamed side characters.
15.2
Shou's unnamed group.
black ponytail calls out to Segawa
brown and short black glare at Shou and sweatdrop in the elevator.
brown is bold, shorthair whiny.
ponytail mocks Shou "you miss your mama that much".
brown "I can see it, Koumoto is caring"
short "I think Segawa is cool, no bully"
ponytail "You're too soft on her"
16
Shou gets dumped by her group
brown pushes back at Shou for wanting to go slow
ponytail plays peacemaker, suggests split
ponytail waves goodbye
17
cave
ponytail has camera and is Komatsu.
brown teases her.
ponytail tries to tease Shou.
shorthair whines about it being wet.
ponytail asks Segawa about the cave fish, kind of praises her, hits her in a "friendly" but painful way ("ow")
gift shop
brown lectures her on gifts. Of course, Shou only has dad (lame) and Umi (already here)
ponytail teases Shou about still being rebellious
Ponytail is a lot like Yosshi. Aggressively teasing to the point of bullying, and likely justifies it as policing proper behavior, but also tries to keep the group functioning and suggest compromise.
I kind of want to say brown is like Ibu, except Ibu is never as nice. Yeah, brown is being pushy about Shou getting gifts, but she's genuinely trying to be helpful. So maybe more like another Yosshi.
Shorthair is her own wet-noodle personality, no obvious equivalent. Nervous about Shou, also thinks she's cool, speaks up once, otherwise just whines in the background.
It's just a bad group dynamic
Yeah, they're not my favorite people, but not obviously terrible. Just bad for Shou.
she was with Umi's group they vibed really well.
On the flip side, that's not great evidence for Shou not being neurodivergent. Umi's group is a bunch of sweethearts, especially Nae, who is either a really nice person or is out to be really welcoming to Umi's friend. (A bit too nice, practically hitting on her.) You would have to be as prickly as Ibu to not vibe with that group, especially while waiting for your AWOL girlfriend.