Prostitution in Japan has existed throughout the country's history. While the Anti-Prostitution Law of 1956 states that "No person may either do prostitution or become the customer of it," loopholes, liberal interpretations and loose enforcement of the law have allowed the sex industry to prosper and earn an estimated 2.3 trillion yen ($24 billion) per year.
In Japan, the "sex industry" (fuzoku 風俗, literally "public morals") is not synonymous with prostitution. Since Japanese law defines prostitution as "intercourse with an unspecified person in exchange for payment," most fuzoku offer only non-coital services, such as conversation, dancing, or bathing, to remain legal.
NOTE: But remember "Prostitution Selling/Buying" is illegal in Japan. You just need to know what prostitution mean.