It's because in ancient china, 12 is the age of consent and most children get married at this age. But you guys need to understand that back then almost 40%-50% of children die before reaching adulthood. So life expectancy is really low. eitherway most author just use this setting. Read more Read more We could probably agree in modern times that this age is too young so its really gross. Well its gross but thats what reality back then. Show less