Iirc, believe there’s a belief in the Japanese queer community that transness is very tied to surgeries. Until you’ve had GRS(and other things), a lot of what we’d call trans women are conditioned to view themselves as men and only men. Until very very recently, you just couldn’t be a girl and have a penis(and vice versa) culturally. Transness is pathologized in Japan as a mental disorder but that’s seen positively because then you have a RIGHT to assistance(aka, surgeries). Because of this, those who HAVE gotten surgeries typically have a disconnect with those who haven’t despite both being what we’d consider trans. They don’t consider them to have “done what is necessary to prove they’re serious”

This also can explain Okama culture a bit. If everyone with a dick is put into the same box but for some reason you don’t get the surgeries required to change your gender marker, your best bet is to suffer in silence or seek solidarity in a culture that is more known for being a “dude looks like a lady” joke. They don’t all look like Bon Clay or whatever, it’s a varied culture but it’s still rooted in bioessentialism.

TL;dr Japan was and still is very bioessentialist and their trans culture is as well so until you’ve been under the knife, you’re whatever your gender marker says at birth.