A comprehensive list of manga that feature transgender characters and themes. I'm still evaluating some other manga, but if there are any I've left out, or if you find an error, PLEASE let me know in the comments. ...
Manga about gender that I might actually recommend
This is a complete list of every manga and light novel published in English by Digital Manga Publishing and their imprints, DokiDoki, Lilyka and 801 Media. These are either incomplete, ongoing or fully published in English.