Responses

I think gender and sex are both different. Sex is when you are born with male or female body parts. Gender is more on the mindset. So if a boy who has male body parts is a woman at heart, then she's a trans woman. Or if a girl who has female body parts is a man at heart, then he's a trans man. Then there are also genderfluid and genderless ones. Gender is more of a social construct, while sex is biology.
I can't tell whether the uke is a gay man or a straight trans woman that doesn't realise they are trans.... Like.... there is a difference between being a gay man that likes feminine things and a trans woman, but the translator treats these two concept like they are synonymous. I am not sure whether this is the same in the raw version, so I can't determine the thought process of the author. That being said, this lack of clarity shows that the translator and/or the author need to educate themselves so that they can write characters that actually make sense.