Although this falls generally under "modern" Japan, I think it is
applicable:
Japan's PM backs option of empress
By Deborah Cameron
December 4, 2004
Tokyo: Japan is ready for a female emperor and is moving closer to
changing the law passed in 1947 that reserved the Chrysanthemum
Throne for men only, according to Japan's Prime Minister, Junichiro
Koizumi.
"Reigning empresses existed in Japan in the past," he said. "I think
the public will welcome an empress in the present day. I don't think
there will be many problems." With his comments, the Prime Minister
was buying into Japan's hottest topic: the problem that there are no
males to succeed the current heir, 43-year-old Crown Prince Naruhito.
Emperor Akihito is 71 and in 2002 had surgery for prostate cancer,
although he appears to have made a full recovery.
But concerns about succession in the world's oldest hereditary
dynasty have lead to reports this week in the Asahi Shimbun
newspaper of a government "feasibility study" on the idea of a
female heir.
Only if there is a change can the throne one day be occupied by
Princess Aiko, the only child of the Crown Prince and his 41-year-
old wife, Princess Masako.
Crown Prince Naruhito's younger brother, Akishino, also has no sons,
and a male from another branch of the ruling family would inherit
the throne.
http://www.smh.com.au/news/World/Japans-PM-backs-option-of-
empress/2004/12/03/1101923338147.html?oneclick=true