The opening pages of Fumi Yoshinaga's Ooku: The Inner Chambers (Viz Signature) establish its alternate world setting briskly: set in 18th century Japan, the series' first volume opens on a cute young "monkey boy" named Sadakichi who ventures into the mountains to fetch some mushrooms for his mother. He's brought back down from the mountains, bloodied and feverish, carrying a plague that strikes the young men of his village. The pestilence swiftly sweeps across the island country, killing 80% of the male population. (The plague does not appear to cross the water since we later meet a Dutch envoy who knows nothing about it.) Eighty years later, women have taken on the leadership roles in this once strong patriarchy, while the parcel of surviving men are held "with extreme care as precious seed bearers."
The one place where young males aren't used as baby makers is the palace of the shogun. Said to contain 3000 of the country's most beautiful men (though, in actuality, the number is closer to 800), the Inner Chambers represent the "height of luxury in a time of scarcity," though for those young men who actually enter the chambers, it proves a seething setting filled with jealousy, feverish social battles and intrigue. Our eyes into the Inner Chambers belong to a handsome 19-year-old named Mizuna Yunoshin, born of a poor family, who looks at his entrance as a way of supporting his parents and sister without having to marry into money. He doesn't realized just how treacherous palace life can be until it's too late.
Within the chambers, there's a strict hierarchy: first divided between those who are deemed worthy enough of their liege's sight and those who aren't. When Yunoshin enters into service, he arrives in the lowest rank of houseboy, but it isn't long before he leaps into the upper tiers. A much more active and traditionally "manly" youth than many of the preening sons of the wealthy who primarily populate the Inner Chambers, he immediately stands out after he fights off a trio of his peers who attempt to "initiate" him by forcing him to "play the woman." He also draws the attention of the Machiavellian senior chamberlain Fujinami, who quickly realizes the disruption to the strictly maintained social order that Yunoshin presents.
Yoshinaga deftly delineates the social mores and social maneuvering in her hermetic setting. If she occasionally over-hammers the gender switch aspect of her storyline ("That is no different from the spiteful tormenting of indentured apprentices by the women of a merchant's house," Yunoshin says of his peers at one point), most of this is in tune with Ooku's community of emotionally stunted young men. In a world where having a "pale pretty face and impeccable manner of social conduct" bests swordsmanship, it's inevitable that an excess amount of foppish posturing will take place.