Koukyuu Kisaki no Kanrinin

Yuuran, the daughter of a prominent merchant, was married quickly due to an imperial order requiring her to oversee the imperial harem. Her husband is the younger, attractive right prime minister, though she apologizes to him for marrying someone her own age. Upon beginning her duties at the palace, she meets a woman who apologizes for her appearance and reveals herself to be Yuuran's husband. The pair must navigate the harem together, with the husband disguised as a woman.