Recently read volume 2 of Ôoku.
This is an alternative history of Edo Period Japan in which a severe disease has hit the country that kills most males during their adolescence. Japan is able to close it's borders before the Europeans find out and a new society grows where women take a dominant role and men are treated with great care. In this Japan the shogun is now a woman.
In the first volume you are introduced to this Japan, in the second it goes back to the early history when the red pox was fairly new. What's fun for me is that many of the characters are from history and the author has done considerable research on the persons and customs of the times.