Ōoku takes place in an alternate-history Japan where a plague that affects only men has wiped out a large chunk of the male population, so that the ratio of females to males is something like 4:1. Partly out of sheer numbers and partly to protect men (for example, from injury or accidental death) most jobs are done by women, including holding political position. The actual Ōoku of the title is the shogun’s harem, the shogun, of course, being a woman; and in a world where most women will never marry and have children by paying men to impregnate them, a harem is perhaps the ultimate “conspicuous consumption” and expression of the shogun’s power.

Really one of the most interesting things I’ve read in a while.