
Kinosaki has never said anything about identifying one way or another. At the beginning, he told Gero that if he dressed as a boy, the girls wouldn't fall for Gero so he decided to keep dressing as a girl. Seems more like a hobby, but it hasn't been addressed recently, just right at the beginning of the manga.

i personally project genderfluid onto him bc thats what i identify as but likejejdh i will not be upset at whatever canon gender she has as LONG AS IT'S NOT "secretly cis woman" holy crap like literally anything else i will be jolly with. no matter what they end up identifying as, gerosaki's relationship will always be queer
I wonder if kinosaki is gender fluid ? I hate my terrible memory… when I have time I’ll reread I just hope I haven’t been misgendering him or something