At the time of this writing, Kamikawa Aya has been Japan’s only openly transgender elected official. After a frustrating experience reaching out to local politicians to gain recognition for transgender issues, she took their advice and ran for office herself. Originally elected in 2003 on an independent ticket, she has held her regional assembly seat through (at least) 2014. She is involved with an underground think-tank for LGBT political voices; spoken at a coming-of-age ceremony especially for Japanese LGBT youth; and been interviewed regarding her views on Japanese media programming that features transgender characters.
Although Kamikawa has become famous due to her work on behalf of the trans community, she is also known for advocating on behalf of other underrepresented groups, including people with disabilities and students. Her website (largely in Japanese) can be found here.