RW readers would probably be interested in knowing that there is a large sub-genre of manga that focuses on sex changes and transgender transformations.
Illustration from Urce-Lu 01. Click on image to enlarge!
I readily admit that I am no expert in Japanese culture, but it seems to me that transgender themes are a little bit more mainstream in Japan than in the US or Europe.
The term used in Japan is apparently TSF (with latin letters!) or transsexual fiction.
Although it is easy to find translated manga in the West, it is not easy to pinpoint TG comics. Fortunately there are TG manga enthusiasts out there that are willing to share their love for the artform.
Illustration from Kiwamete Kamoshida by Naoshu Yamamoto.
The best TG manga site I know of is Fahrad's TG Manga site, which includes a large number of Japanese TG comics stored as jpeg files. There is one jpeg per comic book page.
Needless to say, it takes some time to download a complete book, but the effort is definitely worth it for many of them.
Quite a few, but not all, are translated into English. Still, do remember to read the panels from right to left.
My favorite is Yume Demo Iretai, a body swap story by Akagiryuu focusing on our protagonist's exploration of his new female body. All right, it is pornographic, but well done!
If you want to discuss transgender manga, you can go to Farhad's TG Manga Forum over at the Fictionmania IRC. In this forum you will also find links to more files.
And even more files can be found over at Yahoo! Groups. Go to mangatg, which is the first of five such groups.
For more about TG manga, see Jana’s TG Manga And Anime Pages. (Anime means Japanese animations).
If you are more into the cross-dressing theme and/or intersexuality than sex changes, look at Jana's TG Manga and Anime Journal.
Page from Yume Demo Iretai. Click on image to enlarge!
There are many Japanes sites devoted to TG manga, but given the Japanese script they are close to impossible to navigate for a Non-Nipponese. You could take a look at TSF Review Revolution though. Here is a link to a Google translation.
See also the Wikipedia's list of Transgender Anime and Manga
UPDATE: I now realize that Fahrad has a new site that is to replace the old one.