There are an estimated 50,000 women from South Korea working in the sex trade in Japan. In the United States, there are an estimated 30,000 South Korean prostitutes.
Media reports state that the number of Korean prostitutes in Japan was caused by a 2004 crackdown on the sex trade in South Korea, thus sending women to Japan. With the increase in South Korean prostitutes, the prices for sex has reportedly gone down.
In 2012, it was reported that men were paying around $125 (10,000 Japanese Yen) to have sex with prostitutes for a 60 minute session. Previously, the rate was $187 (15,000 Yen) per hour.
Source: Kazutaka Shimanaka, “Enough Korean hookers in Japan to fill a stadium,” Tokyo Reporter, May 30, 2012.