I don't remember much about any of the participants or the dolls..

Hinako:
She hung around Midori a lot, but otherwise I don't know. I think she was like 13?

Kai:
My brother, we were close. He was trans. he tied up his hair in a short ponytail all the time. his hair was kinda a really dark grayish brown?

Alice and Reko:
I can't remember anything other than they had dark skin, and whenever I think of them I feel guilty

Chidouin:

she had a normal ponytail, no braid, and her outfit was black and white (i'll draw it later), she was tan and had freckles, definitely got sunburns a lot