To be fair, Kanechika senpai may wear heels to get used to walking in heels (for the play) and was wearing a skirt later on because he just had a play. There's nothing to indicate that he usually wears a skirt and heels, or acts or behaves like a girl. In fact, using "boku" indicates he does not. Nao-chan, however, does look like she lives as a woman. As to what she does, it is a fact that there are limited job opportunities for a transgender person in Japan, but it looks like she keeps a normal commuting hours and is home in the evenings. So that hints at a professional setting where she may not have to interact with the general public very much, which is pretty much all non-sales office jobs...