Show is Yoru no Kurage wa Oyogenai - Jellyfish can't swim in the night
Probably spoilers. Last warning.
spoiler
Here: https://yorukura.fandom.com/wiki/Kiui_Watase
I did this based on this scene from episode 11: https://streamable.com/oq226r
Comrade Kiui is FtM.
Not only that but his name "Watase" splits into "Wata" which means "crossing" or "ferry," often used in Japanese names to imply traversing a river or similar feature, hinting at transitions or change. While "se" meaning "rapids" or "change" is also another blatantly huge clue.
I haven't worked out what Kiui might reference, it's written in Katakana and some think it's the Kiwi bird. I don't know if this is related or not, someone else might.
QED
EDIT: Edit war has begun.
Maybe! I get the impression that they're in some sort of stage of figuring themselves out. The thing is that as Kiui they clearly hate themselves to the point of literally hiding their face from other people on the street, they don't want other people to even perceive them, they don't feel right in their own skin and the "your body just keeps growing on its own" is obviously referring to boobs growing. So if it does end up being non-binary the obvious take is that they would present as masc.
yeah the gender dysphoria thing is very clear! i dont exactly wanna go back & look at the episode rn but I'm pretty sure they do also say during the confrontation at the arcade that they were basically building their vtuber avatar as an idealised self. ofc it's left ambiguous exactly how kiui wishes to be referred to so i'm sure they'll clarify it a bit more later (or maybe not since queer shit tends to just get twelve episodes :P)
I'm hoping that going forwards they end up dropping Kiui as a name and switch to Nox fulltime.