In his book, Fuzoku Eigyo Torishimari (Control of Sex Business Operations), Kansai University professor Yoshikazu Nagai, documents that Soaplands exploit this to provide intercourse. The customers pay an entry fee to 'use the bathing facilities' and a separate fee to the masseuse. Whilst the massage takes place, the two become 'acquainted' so any paid sexual services that follow are not viewed as prostitution as defined by the law.