I totally agree! At first I thought he was just really into drag but it really felt like the author was depicting serious gender dysphoria when he would be seen without women's clothing and makeup, like when they were out on their date together. So even if he doesn't identify as a trans woman necessary, I don't believe he's cis (not that dysphoria is the only way to validate trans identity ofc, just that it felt like a good indicator)
Also, since the concept of transness is different between cultures, that might play into how he identifies and how that might be different from how he might identify were he from a more western setting (if that makes sense)
really cool to see this kinda stuff idk if ive ever seen a yaoi that gives this raw of a gender/sexuality narrative
seme definitely has trans experiences and i kinda hope the author doesnt sugarcoat that