Yupp, good question. But since it is Japan it is very well regulated whom one calls a shemale and a cross dresser. Here an excerpt from the website from sakura-moon:
[What is a transsexual / transvestite (male daughter)? ]
At our shop, we categorize cast members who normally live as women and take female hormones as "transsexuals", and casts who normally live as men and dress up as women as "transvestites".
About female hormones
In general, if you take it, your skin will become finer and paler, your body and facial lines will become more feminine, and your breasts will become larger.
NH (transsexual) has a high sense of beauty and is devoted to body care, so she is much more feminine than women who are less conscious. Her voice is often feminine.
Don't worry, just because a cross-dresser is cross-dressing doesn't mean that she has a full beard or that she hasn't trimmed her shin hair.
In addition, as a classification unique to NH Health,
There are "with" / "with" / "without".
"Ari Ari" is a pole ant and a ball ant
"There is no" is a pole ant, a ball pear
"None and none" is neither
I've never heard of "Nashiari".
*If you remove the ball, the male hormone will be suppressed, making it more feminine.
Here the link to the website:
Sakura-moon
They even have a small manga explaining what to expect from a session..very well organized.