The story takes place in an alternate version of Japan’s Edo period, where a mysterious plague has decimated the male population, reducing it to a quarter of the female population. This demographic shift has forced a complete reversal of gender roles: women now hold positions of power as rulers, warriors, and heads of households, while men are sheltered and treated as valuable assets for reproduction. At the height of this society’s prosperity, known as the Genroku era, the fifth Tokugawa shogun is a woman named Tsunayoshi.

Despite her political success, Tsunayoshi is deeply isolated within the walls of Edo Castle. She is tormented by loneliness and insecurity, constantly seeking emotional comfort from the three thousand handsome men who live in the Ooku, the shogun’s inner chambers that have become a male harem. Her situation grows desperate after the sudden death of her only daughter, Matsuhime, the sole heir to the dynasty. The pressure to conceive a new successor intensifies, and Tsunayoshi is compelled to take countless men to her bed each night without even being allowed to properly mourn, a routine that leaves her feeling like a vile woman.

Into this volatile political landscape enters Emonnosuke, a brilliant but impoverished court noble from Kyoto who bears a striking resemblance to Arikoto, a man beloved by a previous shogun. Emonnosuke is darkly charismatic and lives for power rather than love. He quickly navigates the bitter factional struggles of the Ooku, winning the trust of the vulnerable Tsunayoshi and rising to the position of general supervisor, the chamberlain of the inner palace.

As Emonnosuke maneuvers in secret to use the shogun to fulfill his own ambition, he finds himself unexpectedly moved by Tsunayoshi’s anguish. Her suffering is compounded by the schemes of her doting but deluded father, Keishoin, who issues impractical decrees such as a ban on killing animals, throwing the country into turmoil. When Tsunayoshi loses the will to live after being made sport of by fate, the person who reaches out to her is Emonnosuke, who has been silently watching over her for decades. A man who lives for power and a woman trapped by her destiny finally establish an emotional bond, struggling to find peace in a world torn apart by plague and political intrigue.