In 1594, after the second invasion of Joseon, Toyotomi Hideyoshi determined to conquer Korea, was repelled by the Korean forces allied to the Ming Chinese.
The Japanese captured tens of thousands of Korean farmers and artisans, bringing them back to Japan for enslavement.
Sebastian of Portugal feared that this was having a negative effect on Catholic proselytization since the slave trade in Japanese was growing to larger proportions, so he commanded that it be banned in 1571.
[7][8] However, the ban failed to prevent Portuguese merchants from buying Japanese slaves and the trade continued into the late 16th century.
[11][12] When Japan invaded Joseon, Korea in 1592, the Japanese abducted huge numbers of Koreans and sold them into slavery.
Hideyoshi, despite enslaving Korean slaves for himself, was bothered that his own people were being sold into slavery on Kyushu, that he wrote a letter to Jesuit Vice-Provincial Gaspar Coelho on 24 July 1587 to demand the Portuguese, Siamese (Thai), and Cambodians stop purchasing Japanese and return Japanese slaves who ended up as far as India.
In a Jesuit statement released in 1598, when they excommunicated merchants who engaged in slave trade in Japan, the situation was described as follows: "Innumerable Joseon subjects (Koreans) are being abducted and sold off at cheap prices (by the Japanese)".
[33] In the 19th and early 20th centuries, there was a network of Japanese prostitutes being trafficked across Asia, in countries such as China, Vietnam, Korea, Singapore and India, in what was then known as the 'Yellow Slave Traffic'.
According to a joint study by historians including Zhifen Ju, Mitsuyoshi Himeta, Toru Kubo and Mark Peattie, more than 10 million Chinese civilians were mobilized by the Kōa-in (East Asia Development Board) for forced labour.
[40] During World War II the Japanese empire used various types of foreign labor from its colonies, Korea and Taiwan.
[45] Since the end of the Second World War, numerous people have filed lawsuits against the state and/or private companies in Japan, seeking compensation based on suffering as the result of forced labor.
The plaintiffs had encountered many legal barriers to be awarded damages, including: sovereign immunity; statutes of limitations; and waiver of claims under the San Francisco Peace Treaty.
[46] According to the United States House of Representatives House Resolution 121, as many as 200,000 "comfort women" [47] mostly from Korea and China, and some other countries and territories such as the Philippines, Taiwan,French Indochina (Vietnam),Burma, the Dutch East Indies, Netherlands,[48] and Australia[49] were forced into sexual slavery during World War II to satisfy Japanese Imperial Army and Navy members.
However, a later decision by the Seoul Central District Court created confusion by dismissing a case against Japanese firms, citing the 1965 Agreement on the Settlement of Problems concerning Property and Claims and on Economic Cooperation, which Japan argues settled the matter of compensation.
UNESCO highlighted Japan's failure to adequately acknowledge the use of Korean forced labor at these sites during World War II.