Ōoku: The Inner Chambers

Ōoku: The Inner Chambers (大奥, Ōoku) is an ongoing Japanese manga series written and illustrated by Fumi Yoshinaga. The manga has been serialized in Hakusensha's josei magazine Melody since 2005. Hakusensha has released thirteen tankōbon volumes to date, starting in September 29, 2005. The manga is licensed in North America by Viz Media and in Taiwan by Sharp Point Press. It was adapted into a live-action film in 2010 and it was adapted into a TV drama series and another live-action film in 2012.

Plot
In an alternative timeline of feudal Japan, a strange disease that only affects men has caused a massive reduction of male population, thus women have to pick up men's jobs, changing the social structure. Now, after 80 years of the initial outbreak and current man:woman ratio of 1:4, Japan has become completely matriarchal, with women holding important political positions and men being their consort. Only the most powerful woman—head of Tokugawa shogunate—can keep a harem of handsome yet unproductive men, known as "Ooku."