Ooku: The Inner Chamber (2012)

In the Edo era during the reign of the third shogun, a mysterious smallpox epidemic affects males only, causing the number of males to plummet to one-fourth of the population. The roles of males and females are reversed. Women run businesses and politics. A young girl takes the seat as the heir of the shogunate and becomes the first female shogun. She is Tokugawa Iemitsu. When Iemitsu turns 16, the pure-hearted Madenokoji Arikoto, who heads a temple, is threatened and forced to return to secular life. Together with his disciple Gyokuei, he becomes one of the 3,000 handsome concubines that wait on the shogun in the inner palace.