Koreans constitute the second largest ethnic minority group in Japan after Chinese immigrants. The majority of Koreans in Japan are Zainichi Koreans, often known simply as Zainichi: ethnic Koreans who immigrated to Japan during the Japanese rule of Korea and are citizens or permanent residents of Japan, and their descendants. Other waves of Korean immigration have occurred, both before and after, most recently during the 1980s.
Terminology The term Zainichi Korean refers only to long-term Korean residents of Japan who trace their roots to Korea under Japanese rule, distinguishing them from the later wave of Korean migrants who came mostly in the 1980s, and from pre-modern immigrants dating back to antiquity, possibly including the Yayoi people who constitute the biggest ancestral group of the Japanese people. Zainichi Koreans are a distinct group from South Korean nationals who have immigrated to Japan since the end of World War II and the division of Korea.
The Japanese word itself means a foreign citizen "staying in Japan", and implies temporary residence. Nevertheless, the term "Zainichi Korean" is used to describe settled permanent residents of Japan, both those who have retained their Joseon, North Korean or South Korean nationalities, and even sometimes includes Japanese citizens of Korean descent who acquired Japanese nationality by naturalization or by birth from one or both parents who have Japanese citizenship.
Korean Japanese refers to Koreans residing in Japan who hold Japanese nationality, rather than South Korean or North Korean nationality. In everyday usage, the term is sometimes discussed alongside Zainichi Koreans, although some sources continue to distinguish between and due to the continued presence of residents who retain or are affiliated with Chongryon.
Population Many commentary has advanced broader estimates for the total number of people of Korean descent in Japan when including naturalized Japanese citizens and their descendants. A Chosun Ilbo article, drawing on reporting based on Tokyo correspondent observations and interviews, described figures in the range of four million as commonly cited and presented roughly four million as a realistic estimate. The same commentary also stated that Mindan (the Korean Residents Union in Japan), an organization representing portions of the Zainichi Korean community and supported by the government of the Republic of Korea, has cited a similar estimate.
The Zainichi population declined significantly due to death, returning to Korea, and assimilating into the general Japanese population.
According to the Ministry of Justice, 407,341 South Koreans and 22,201 North were registered as permanent or non-permanent residents of Japan in 2025.令和7年末現在における在留外国人数について Below, two statistics on the numbers of foreign residents living in Japan are displayed, one map and one chart:
History
Overview The modern flow of Koreans to Japan started with the Japan-Korea Treaty of 1876 and increased dramatically after 1920. During World War II, a large number of Koreans were also conscripted by Japan. Another wave of migration started after South Korea was devastated by the Korean War in the 1950s. Also noteworthy was the large number of refugees from the massacres on Jeju Island by the South Korean government.
Statistics regarding Zainichi immigration are scarce. However, in 1988, a Mindan youth group called Zainihon Daikan Minkoku Seinendan published a report titled, "Father, tell us about that day. Report to reclaim our history" . The report included a survey of first-generation Koreans' reasons for immigration. The result was 13.3% for conscription, 39.6% for economics, 17.3% for marriage and family, 9.5% for study/academic, 20.2% for other reasons and 0.2% unknown.1988 The survey excluded those who were under 12 when they arrived in Japan.
Pre-modern era While some families can currently trace their ancestry back to pre-modern Korean immigrants, many families were absorbed into Japanese society and as a result, they are not considered a distinct group. The same is applicable to those families which are descended from Koreans who entered Japan in subsequent periods of pre-modern Japanese history. Trade with Korea continued to modern times, with Japan also periodically receiving missions from Korea, though this activity was often limited to specific ports.
Yayoi period In late prehistory, in the Iron Age Yayoi period (300 BCE to 300 CE), Japanese culture some Korean influence, though whether this was accompanied by immigration from Korea is debated (see Origin of the Yayoi people).
Kofun period (250 to 538) In the later Kofun (250–538 CE) and Asuka (538–710 CE) periods, there was some flow of people from the Korean Peninsula, both as immigrants and long-term visitors, notably a number of clans in the Kofun period (see Kofun period Korean migration). While some families today can ultimately trace their ancestry to the immigrants, they were generally absorbed into Japanese society and are not considered a distinct modern group.
Heian period (794 to 1185) According to the Nihon Kōki historical text, in 814, six people, including a Silla man called Karanunofurui (, Japanese: 加羅布古伊; presumed to be of gaya descent) became naturalized in Japan's Minokuni region.
Sengoku period (1467 to 1615) Some 60-70,000 Koreans were taken to Japan as prisoners of war during the 15921598 Japanese invasions of Korea. Notable individuals include Kang Hang.
Edo period (1603 to 1867) In the Edo period, trade with Korea occurred through the Tsushima-Fuchū Domain in Kyūshū, near Nagasaki.
Before World War II
After the conclusion of the Japan-Korea Treaty of 1876, Korean students and asylum seekers started to come to Japan, including Korean politicians and activists Pak Yŏnghyo, Kim Okkyun, and Song Pyŏngjun. There were about 800 Koreans living in Japan before Japan annexed Korea. In 1910, as the result of the Japan–Korea Annexation Treaty, Japan annexed Korea, and all Korean people became part of the nation of the Empire of Japan by law and received Japanese citizenship.
In the 1920s, the demand for labor in Japan was high while Koreans had difficulty finding jobs in the Korean peninsula. As a result, thousands of Koreans migrated or were recruited to work in industries like coal mining. A majority of the immigrants consisted of farmers from the southern part of Korea. The number of Koreans in Japan in 1930 was more than ten times greater than that of 1920, reaching 419,000. However, the jobs they could get on the mainland of Japan were curtailed by open discrimination and largely limited to physical labor due to their poor education; they usually worked alongside other groups of ethnic minorities subject to discrimination, such as burakumin.
Before World War II, the Japanese government tried to reduce the number of Koreans immigrating to Japan. To accomplish this, the Japanese government devoted resources to the Korean peninsula.
During World War II
In 1939, the Japanese government introduced the National Mobilization Law and conscripted Koreans to deal with labor shortages due to World War II. In 1944, the Japanese authorities extended the mobilization of Japanese civilians for labor on the Korean peninsula. Of the 5,400,000 Koreans conscripted, about 670,000 were taken to mainland Japan (including Karafuto Prefecture, present-day Sakhalin, now part of Russia) for civilian labor. Those who were brought to Japan were forced to work in factories, in mines, and as laborers, often under appalling conditions. About 60,000 are estimated to have died between 1939 and 1945.Available online: Most of the wartime laborers returned home after the war, but some elected to remain in Japan. 43,000 of those in Karafuto, which had been occupied by the Soviet Union just before Japan's surrender, were refused repatriation to either mainland Japan or the Korean Peninsula, and were thus trapped in Sakhalin, stateless; they became the ancestors of the Sakhalin Koreans.
After World War II Koreans entered Japan illegally post-World War II due to an unstable political and economic situation in Korea, with 20,000 to 40,000 Koreans fleeing Syngman Rhee's forces during the Jeju uprising in 1948. The Yeosu-Suncheon rebellion also increased the illegal immigration to Japan. It is estimated that between 1946 and 1949, 90% of illegal immigrants to Japan were Koreans.昭和27年02月27日 13-参-地方行政委 鈴木一の発言 「一昨年の十月から入国管理庁が発足いたしまして約一年間の間に三千百九十名という朝鮮人を送り帰しておる。今の密入国の大半は、九〇%は朝鮮人でございます」 During the Korean War, Korean immigrants came to Japan to avoid torture or murder at the hands of dictator Syngman Rhee's forces (e.g., in the Bodo League massacre).
Fishers and brokers helped immigrants enter Japan through Tsushima Island.昭和25年11月01日 8-衆-外務委「朝鮮人の密入国は 対馬を基点といたしまして、その周辺の各県にまたがる地域が圧倒的数字を示しており、 大体全国総数の七割ないし八割が同方面によつて占められているという状況であります。」 In the 1950s, Japan Coast Guard secured the border with Korea, but apprehending illegal immigrants was difficult because they were armed, while Japan Coast Guard was not due to the terms of the surrender of Japan after World War II. During this period, one-fifth of the immigrants were arrested.
In Official Correspondence of 1949, Shigeru Yoshida, the prime minister of Japan, proposed the deportation of all Zainichi Koreans to Douglas MacArthur, the American Supreme Commander of the Allied Powers, and said the Japanese government would pay all of the cost. Yoshida stated that it was unfair for Japan to purchase food for illegal Zainichi Koreans, claiming that they did not contribute to the Japanese economy and that they supposedly committed political crimes by cooperating with communists.
Loss of Japanese nationality
Immediately following the end of World War II, there were roughly 2.4 million Koreans in Japan; the majority repatriated to their ancestral homes in the southern half of the Korean Peninsula, leaving only 650,000 in Japan by 1946.
Japan's defeat in the war and the end of its colonization of the Korean Peninsula and Taiwan left the nationality status of Koreans and Taiwanese in an ambiguous position in terms of law. The of 2 May 1947 ruled that Koreans and some Taiwanese were to be provisionally treated as foreign nationals. Given the lack of a single, unified government on the Korean Peninsula, Koreans were provisionally registered under the name of Joseon (, Japanese: Chōsen, ), the old name of undivided Korea.
In 1948, the northern and southern parts of Korea declared independence individually, making Joseon, or the old undivided Korea, a defunct nation. The new government of South Korea made a request to the Supreme Commander of the Allied Powers, then the occupying power of Japan, to change the nationality registration of Zainichi Koreans to Daehan Minguk (; ), the official name of the new nation. Following this, from 1950 onwards, Zainichi Koreans were allowed to voluntarily re-register their nationality as such.
The Allied occupation of Japan ended on 28 April 1952 with the San Francisco Peace Treaty, in which Japan formally abandoned its territorial claim to the Korean Peninsula, and as a result, Zainichi Koreans formally lost their Japanese nationality.United Nations International Convention on the Elimination of all Forms of Racial Discrimination (September 26, 2000): "E. Korean residents in Japan 32. The majority of Korean residents, who constitute about one third of the foreign population in Japan, are Koreans (or their descendants) who came to reside in Japan for various reasons during the 36 years (1910–1945) of Japan's rule over Korea and who continued to reside in Japan after having lost Japanese nationality, which they held during the time of Japan's rule, with the enforcement of the San Francisco Peace Treaty (28 April 1952)."