

Traders of the various European East India Companies, including those of the Dutch and British, engaged the services of prostitutes while visiting or staying in Japan. When the Europeans ( Nanbanjin) came to Japan, they too patronized Japanese prostitutes. In Sakai and Hakata ports, Japanese brothels had already been patronized by Chinese visitors far before Europeans came to Japan. In 1505, syphilis started to appear in Japan, likely because of Japanese prostitutes having sex with Chinese sailors. Anti-Portuguese propaganda and exaggerations were actively promoted by the Japanese, particularly with regards to the Portuguese purchases of Japanese women for sexual purposes.

They bought or captured young Japanese women and girls, who were either used as sexual slaves on their ships or taken to Macau and other Portuguese colonies in Southeast Asia, the Americas, and India, where there was a community of Japanese slaves and traders in Goa by the early 17th century. Portuguese visitors and their South Asian and African crew members (or slaves) often engaged in slavery in Japan. More than hundreds of Japanese people, especially women, were sold as slaves. These mistaken assumptions were due to the Indian state of Goa being a central base for the Portuguese East India Company at the time, and due to a significant portion of the crew on Portuguese ships being Indian Christians. This began with the arrival of Portuguese ships to Japan in the 1540s, when the local Japanese people assumed that the Portuguese were from Tenjiku ( 天竺, "Heavenly Abode"), the ancient Chinese name (and later Japanese name) for the Indian subcontinent, and thus assumed that Christianity was a new Indian religion. This practice later continued among visitors from "the Western regions", mainly European traders who often came with their South Asian lascar crew (in addition to African crew members in some cases).

From the 15th century, Chinese, Koreans, and other East Asian visitors frequented brothels in Japan.
