Most of the other charachters are too. Especially Kei.
Anime characters in general. I suspect it’s because many writers are otaku and that is correlated with autism for sure (the origin of the label is due to the unusually formal speaking patterns the OG otaku had for one)
Honestly, autistic headcanons seem easy to make for a lot of charachters in geek media. Ages ago i saved a post of someone making a good case for all the MCU original Avengers being on the spectrum (though the only MCU charachter that def is is Kingpin).
But yeah, charachters in anime acting neurodivergently is indeed common.
How is Kei and Kaguyas maid autistic?
Because i said so and i am the king of Autism. /s
Idk i cant explain autism headcanons easily but Kei might actually be the most autistic to me based on vibes? But it really is mostly vibes.
Hayasaka though prob is not. But shes in the background of the image and i wasnt really counting her.