Wikipedia
Deuki is an ancient custom practiced in the far western regions of Nepal in which a young girl is offered to the local Hindu temple to gain religious merit.
Girls become deukis either because their parents offer them in hopes of gaining protection and good favor from the Gods or because their parents sell them to wealthier couples seeking the same holy approval. Poor families who offer up their daughters gain status and approval from their communities from the perceived sacrifice they have made. They are also relieved of the burden of finding husbands for their daughters.
After offering the girls to the temples, neither parents nor couples who bought them provide any financial assistance or have additional contact with deukis. Because they are considered unfit for marriage and receive no money from those that dedicated them to their temples, deukis have to depend on worshipers’ monetary offerings to the temple. Left with insufficient income, no skills or education, and pressure brought on by the folkloric conviction that sex with a deuki can cleanse sins and bring good luck, many deukis are driven to survival sex, a form of prostitution in which sex is traded for basic necessities such as food or shelter.
Due to the law stating that Nepalese citizenship falls along the father’s line, daughters born to deukis, known as devis, frequently cannot become citizens of Nepal. Denied access to education and other social services, many devis become deukis. Though a legislative change in 2006 makes it slightly easier for deukis to get citizenship for their children if they can prove that the father is Nepalese, matrilineal descent remains unrecognized.