The Edo period in Japan (1603-1868) saw the emergence of an unusual ailment dubbed the Redface Pox. This affliction had a higher prevalence among men, causing a staggering decline in their numbers to just a quarter of the female population over an 80-year period. As a result, women had to take on traditionally male roles, such as the Shogun position. Men, prized for their reproductive capacity, were closely monitored with the most desirable being selected to serve in the Inner Chambers of the Shogun.