Responses
Another theory is that they represent "lies" the person makes.
There are two different forms of lies, and two different types of star eyes accordingly:
White star eyes represent where characters lie in the name of doing something good
While Black star eyes represent lies where its made maliciously or made for the sake of harming others.
Another thing that was pointed out was that (The red haired girl) had galaxy eyes, which represents the truth, the opposite of star eyes.

Anime watcher here, does anyone know what the star eyes actually are? I thought it was genetic until the other girl (was it Kana?) got them and then I thought it might be a mind set thing (like if they really get in the zone or something?) so I’m mildly confused now.