To be honest, I get the twins, since I learnt more about drag I wanted to try it myself because I just thought "I could look pretty hot" lol so I don't think he would be more of a trans person, but he does seem to have some shared feelings with a trans girl.
I do hope they have trans representation in the future, since the manga seems pretty queer-accepting (at least to me) (=・ω・=)
Hey guys! Thanks for the nice replies, even if we don't agree. At this point, it's just a matter of opinion since the manga has already stated what is "canon".
As a little aside, by attitude towards his male appearance what do you mean exactly? That he's popular and admired by girls? Because he doesn't seem to mind the love and attention "he" receives when dressed as a girl. In fact, he seems to love it.
Anyway, as I said, this is just how I feel. Ootori is canonically a crossdresser but I do feel "he" could very easily be read as a trans girl, which I think is a more interesting interpretation.
Well to me i think Ryuugasaki is the one that could be read as a trans girl. Ootori in my opinion just like cross dressing as his ideal female it’s basically can kinda be interpreted as cosplay. Just like how @yaoi fangirl said Ootori prefers to cross dress not because he feels/thinks he is a girl. The twins is basically just using their looks and the personality of their ideal lover to complete their fantasies. Ootori in my opinion couldn’t be interpreted as a female since he doesn’t believe he a female inside and out. While it’s different with Ryuugasaki so to me he could be interpreted as a trans girl.
But that’s just my opinion! I respect and could agree with your opinion a little bit.

I get that they're all crossdressers but I feel like Ootori is more of a trans girl. "He" is genuinely depressed when living as a man and is only cheerful and open when dressed as a girl. That weird explanation of him falling in love with himself could easily be seen as him liking being a girl much more.
Of course, I'm not actually expecting any meaningful trans representation in a gag manga about crossdressers. ( ̄∇ ̄")