Mui tsai

Mui tsai (Chinese: 妹仔; Cantonese Yale: mūi jái), which means "little sister" in Cantonese, describes young Chinese women who worked as domestic servants in China, or in brothels or affluent Chinese households in traditional Chinese society. The young women were typically from poor families, and sold at a young age, with the condition that they be freed by marriage when older. These arrangements were generally considered as charitable and a form of adoption, as the young women would be provided for better as mui tsai than they would if they remained with their family. However, the absence of contracts in these arrangements meant that many mui tsai were resold into prostitution. According to some scholars, many of these girls ended as either concubines or prostitutes, while others write that their status was higher than a concubine's.

In traditional Chinese culture, a family needs a male offspring. Poor parents, who were unable to support many children, sometimes killed newborn infants if they were female. In consideration of poverty it was an accepted alternative to sell unwanted girls.

The practice was also prevalent before World War II in Hong Kong, Singapore and parts of Southeast Asia.