I think Miyako is a well enough written character with her own personality and quirks that I personally wouldn't call her a self-insert. I love her relationship with her sister and some of those heart warming moments, the really calm moments where she acknowledges and she accepts Hinata even if she's often clingy and energetic. Just my opinion though.
i also like miyako and some of her moments with all the kids kind of reminds me of barakamon and the whole adult learning life lesson by spending time with younger people dinamic
but i do find creepy some of the moments that involve hana and miyako, but well whatever it doesn´t bother me that much
That day Rosehip was found dead behind the St. Gloriana dorms. It seems she was beaten up with a sharp object. Authorities suspect it was a broken teacup
^Aw shucks, I mixed up white and black. If you combine the three primary pigment colors you get black, not white. So of course they were talking about light.