Slavery in Japan existed in several forms from antiquity through the modern period, alongside and proceeding other systems of unfree and coerced labor, some manifestations of which continue to this day. In early Japanese sources, enslaved people included groups referred to as seikō () and later nuhi () under the ritsuryō legal codes, and historians debate how these institutions compare with slavery and serfdom in other societies.
By the late medieval and Sengoku periods, the buying and selling of captives and other dependent people remained widespread, including the export of Japanese people through the Portuguese slave trade in the 16th century. Under Toyotomi Hideyoshi, slavery was officially banned in the late 16th century, but other forms of legally sanctioned coercion and dependency continued, including penal “non-free labor” under early Edo-period law.Lewis, James Bryant. (2003). Frontier Contact Between Choson Korea and Tokugawa Japan, p. 31–32.
In the 20th century, Japan’s wartime empire used large-scale forced labor and prisoner-of-war labor during the Second Sino-Japanese War and the Pacific War, including on projects such as the Burma Railway. The Imperial Japanese military also operated the system of military brothels commonly referred to as “comfort women”, which has been widely described as involving sexual slavery.
Early slavery in Japan The export of a slave from Japan is recorded in the 3rd century Chinese historical record Wajinden, but it is unclear what system was involved, and whether this was a common practice at that time. These slaves were called seikō ( "living mouth").
In the 8th century, slaves were called Nuhi (奴婢) and laws were issued under the legal codes of the Nara and Heian periods, called Ritsuryōsei (律令制). These slaves tended farms and worked around houses. Information on the slave population is questionable, but the proportion of slaves is estimated to have been around 5% of the population.
Slavery persisted into the Sengoku period (1467–1615) even though the attitude that slavery was anachronistic seems to have become widespread among elites.Thomas Nelson, "Slavery in Medieval Japan", Monumenta Nipponica 2004 59(4): 463–492 Somewhat later, the Edo period penal laws prescribed "non-free labor" for the immediate family of executed criminals in Article 17 of the Gotōke reijō (Tokugawa House Laws), but the practice never became common. The 1711 Gotōke reijō was compiled from over 600 statutes promulgated between 1597 and 1696.
War prisoners and Genin During the Sengoku period, Japanese Daimyos and merchants often sold off prisoners of battle into slavery. Portuguese sources, corroborated by Japanese texts like Koyo Gunkan and Hojo Godaiki, describe “the greatest cruelties” inflicted during conflicts such as the 1553 Battle of Kawanakajima and the 1578 Shimazu campaigns. Captives, particularly women, boys, and girls, faced violence, with communities in regions devastated.Thomas Nelson, “Slavery in Medieval Japan,” Monumenta Nipponica59, no. 4 (2004): pp. 479-480, "Fujiki provides a wealth of sources to show just how common the practice of abducting slaves was. Koyo gunkan 甲陽軍鑑, for instance, offers a graphic account of the great numbers of women and children seized by the Takeda army after the Battle of Kawanakajima 川中島 of 1553:.... Hojo godaiki 北条五代記 reveals how systematized the process of ransoming and abduction could become... Reports by the Portuguese corroborate such accounts. In 1578, the Shimazu 島津 armies overran the Otomo 大友 territories in northern Kyushu." The inter-Asian slave trade, including Wokou piracy, further intensified suffering, with Zheng Shungong’s 1556 report noting 200–300 Chinese slaves in Satsuma treated “like cattle” for labor, a fate shared by many Japanese.; doi: 10.1017/S0010417523000270; quote: p.227: two to three hundred Chinese people, “treated like cattle”, originally from Fúzhōu 福州, Xīnghuà 興化, Quánzhōu 泉州, Zhāngzhōu 漳州 p.282: "Forced labor was a sub product of these struggles... Japanese slave market became dependent... on Chinese and Koreans captured by Wakō... servants captured domestically."...
When the Imjin War broke out between Japan with Korean Joseon kingdom between 1592-1598, slavery of Korean captives by three Japanese invaders also occurred. Francesco Carletti, an Italian merchant who visited Japan during that time, was recorded to have bought five Korean slaves for price of about 12 scudi. After baptizing them, he took them to Goa, India, where he set four of them free. It has been suggested that Korean slaves were not traded at high prices, and therefore were cheap. Even if they were bought at low prices, they still needed to be fed on the way, which was an additional expense. Thus, Japanese researcher Watanabe Daimon suspected the reason Carletti freed four of his slaves was possibly because he thought there was no hope of reselling them in the slave market.Watanabe Daimon Kazuo Eno, "Merchant Carletti" (Daito Publishing, 1984)
The custom of geninka (下人化) encompassed practices resembling slavery. Individuals were exchanged for money, including children sold by parents, self-sold persons, those rescued from unjust execution, and debt-bound workers. Japanese rulers imposed geninka as punishment for serious crimes or rebellion, often extending it to the perpetrator’s wife and children.Rômulo Ehalt, Geninka and Slavery: Jesuit Casuistry and Tokugawa Legislation on Japanese Bondage (1590s–1620s), Itinerario (2023), 47, 342–356 doi:10.1017/S0165115323000256, pp. 353-354 Women who fled their fathers or husbands to seek shelter in a lord’s house were sometimes transformed into genin by the lord. During famines or natural disasters, individuals offered themselves as genin in exchange for food, clothing, and shelter. Japanese lords also demanded that retainers relinquish their daughters to serve in their manors, treating them as genin. Additionally, the genin status could be hereditary, perpetuating bondage across generations.Rômulo Ehalt, Geninka and Slavery: Jesuit Casuistry and Tokugawa Legislation on Japanese Bondage (1590s–1620s), Itinerario (2023), 47, 342–356 doi:10.1017/S0165115323000256, p. 354, "The same suggestion was repeated in other cases. For instance, those who offered themselves to work in exchange for protection during events like famines and natural disasters were often considered genin in Japanese society, but confessors were to admonish penitents that they should free these genin upon the completion of enough labour to pay for the amount of food, clothing, and shelter provided."Rômulo Ehalt, Geninka and Slavery: Jesuit Casuistry and Tokugawa Legislation on Japanese Bondage (1590s–1620s), Itinerario (2023), 47, 342–356 doi:10.1017/S0165115323000256, pp. 352-353, "This principle was not limited to the case of genin—social status in general was also often transmitted according to the same gender-based rule: sons taking on that of their fathers, daughters of their mothers....Nevertheless, the authority of the Ritsuryō was always on the minds of early modern Japanese. In 1587, when a group of Japanese visiting Manila was questioned on bondage practices in their country, their response to the fate of genin children replicated the model established by the code.5"Rômulo Ehalt, Geninka and Slavery: Jesuit Casuistry and Tokugawa Legislation on Japanese Bondage (1590s–1620s), Itinerario (2023), 47, p.354, "From the ten titles analysed in Goa, the only case of geninka considered unjustifiable was that of Japanese lords who called upon their retainers to relinquish their daughters to serve in their manors....In the end, missionaries resorted to great sophistication in their arguments out of concern with the religious and legal implications for Christians declaring ownership of enslaved people in Asia and, foremost, with the political and economic consequences missionaries in Japan could face if they decided to condemn these practices."
Portuguese Slave Trade in Japan Background Portuguese merchants in Sengoku-era Japan (1467–1603) viewed unfree labor forms, like master-servant relationships, as slavery, applying terms like criado, servo, and captivo to Japanese classes such as fudai no genin (hereditary servants), genin (lower-class servants), shojū (retainers), and yatsuko (slaves). These groups, often engaged in agricultural or domestic work, were sometimes sold under customary law.Maki, H. (1971). Jinshin baibai [Human trafficking]. Iwanami Shinsho. p.60 The term escravo included nenki hōkō (indentured servants) which was not common until Edo Period, despite their distinct status, causing misunderstandings.Tōkyō Daigaku Shiryō Hensanjo (ed.). Nihon Kankei Kaigai Shiryō –Iezusu-kai Nihon Shokan, Genbun, 3 volumes. Tokyo: Tōkyō Daigaku Shiryō Hensanjo, 1990-2011. I, pp. 77-78 Gaspar Vilela (1557) described peasants as slaves due to economic dependence, while Cosme de Torres likened servants’ subservience to Roman vitae necisque potestas.Tōkyō Daigaku Shiryō Hensanjo (ed.). Nihon Kankei Kaigai Shiryō –Iezusu-kai Nihon Shokan, Genbun, 3 volumes. Tokyo: Tōkyō Daigaku Shiryō Hensanjo, 1990-2011. I, p. 170WESTBROOK, Raymond. “Vitae Necisque Potestas”. In: Historia: Zeitschrift für Alte Geschichte, Bd. 48, H. 2 (2nd quarter, 1999). Stuttgart: Franz Steiner Verlag, 1999, p. 203Juan Ruiz-de-Medina (ed.). Documentos del Japón, 2 Vol. Rome: Instituto Histórico de la Compañía de Jesús, 1990-1995. II, pp. 695-8, p705 Peasants could be sold as tax collateral, blurring free-unfree distinctions.MIZUKAMI Ikkyū. Chūsei no Shōen to Shakai. Tokyo: Yoshikawa Kōbunkan, 1969. Human trafficking was common.OKAMOTO Yoshitomo. Jūroku Seiki Nichiō Kōtsūshi no Kenkyū. Tokyo: Kōbunsō, 1936 (revised edition by Rokkō Shobō, 1942 and 1944, and reprint by Hara Shobō, 1969, 1974 and 1980). pp. 730-2 Some Japanese entered servitude voluntarily for travel to Macau, often breaking contracts upon arrival, driven by civil war taxes.Jesuits and the Problem of Slavery in Early Modern Japan, Rômulo da Silva Ehalt, 2017. p. 473-474, "Cerqueira indicates other failures of the Japanese voluntary servitude system: some would not receive any share of the price paid for their services, which was against the precepts of moral theology; others sold themselves into servitude because were not able to be hired in exchange of wages by the Portuguese, wishing only to pass to Macao. As result of these devious practices, Cerqueira declares that many Portuguese would not buy slaves in the same amount they did before."