For comparison
Meine Liebe and
Saiyuki Reload Gunlock.
So, there are general character design stereotypes that you always come across, things that help to contribute to the justification of who gets to be Seme and who gets to be uke mostly.
Seikimatsu Darling aside, generally as the set rules go the uke gets to be distinctly shorter than the Seme. I suspect that this is half the reason for those height charts you get for every series. But even if the height issue isn’t so pronounced in doujinshi at least, it’ll get fudged just so that it looks right which is fair enough because at the end of the day it looks a bit funny if you’re trying to draw two characters of exactly the same height.
After the generic height difference, there’s also age. Where the Seme is usually older and therefore more experienced than the uke. Though this isn’t really a hard and fast rule at all. Take CLAMP’s
Wish for example, Hisui is decidedly shorter and more delicate than his partner but he’s also quite a bit older and really rather powerful. You might also use Matsushita Yoko’s
Yami no Matsuei as another example because Tzusuki Asato seems to be decidedly older than most other members of the Shoka Division, no matter how childish he might appear to be.
Once we get beyond the basics of height and age, and ignoring for the moment the inequalities caused by rank and station we get on to other basic physical details. Particularly face-wise and this is where my key series for comparison come into the analysis.
( Analysis )