Prostitution, as defined under modern Japanese law, is the illegal practice of sexual intercourse with an 'unspecified' (unacquainted) person in exchange for monetary compensation,[1][2][3] which was criminalised in 1956 by the introduction of article 3 of the Anti-Prostitution Law (売春防止法, Baishun bōshi hō).[1][4] However, the definition of prostitution made illegal under this law is strictly limited to sexual intercourse with an 'unspecified person', and does not criminalise the sale of numerous other acts performed by sex workers in exchange for compensation, such as oral sex, anal sex, mammary intercourse, and other non-coital sex acts; the Businesses Affecting Public Morals Regulation Law of 1948 (風俗営業取締法, Fūzoku eigyō torishimari hō), also known as the "Law to Regulate Adult Entertainment Businesses", amended in 1985, 1999 and 2005,[5] regulates these businesses,[6] making only one definition of prostitution in Japan illegal.
Following the criminalisation of payment for sexual intercourse, the sex industry in Japan has developed into a number of varied businesses and offering services not prohibited under Japanese law. These fall into a number of categories known by various euphemistic names, such as soaplands, fashion health shops, and pink salons, with the term "health" commonly being a euphemism for sexual services. These businesses typically operate out of physical premises, either with their own employees or freelancers such as call girls, who may operate via Internet dating sites known as deai sites (Internet dating sites) or via delivery health services.