Classification: Policy Analysis Report
Date: May 2026
Intended Audience: Researchers, policymakers, and practitioners engaged in international public communication
1. Executive Summary
Purpose
This report examines, from an empiricist standpoint, the structural divergence between the “coercive narrative” surrounding the migration of Koreans to Japan before and after World War II, and the reality of economically motivated, voluntary migration as documented in primary sources.
Central Argument
The majority of population movement from the Korean Peninsula to mainland Japan during the first half of the twentieth century was driven primarily by a significant wage differential between Japan proper (naichi) and the peninsula, and thus bore the character of economic migration. This is substantiated by official statistics of the period, the operational reality of travel certification systems, and primary sources relating to the legal basis of labor mobilization.
Certain contemporary narratives, however, seek to reclassify this historical reality of voluntary economic migration under such labels as “slave deportation” (kyōsei renkō) or “institutionalized racial persecution.” This substitution of terms and concepts undermines academic integrity regarding historical fact and exerts serious influence on ongoing diplomatic and legal disputes.
The presentation of objective fact is the most powerful means of persuasion available to the international community. This report proceeds on that basis.
2. Historical Facts and Background of Migration (Fact Check)
2-1. 1910–1939: The Era of Voluntary Migration and Free Recruitment
Following the annexation of Korea in 1910, the number of Koreans traveling to Japan proper increased steadily. According to statistics compiled by the Home Ministry’s Police Bureau (Naimushō Keihokyoku), the resident Korean population stood at approximately 30,000 in 1920 and had reached roughly 300,000 by 1930 (the census figure by nationality registration for the same year was approximately 420,000). The fact that the resident population grew by approximately 380,000 over this decade — a period in which no state-directed forced mobilization existed — constitutes a significant indicator. The increase during this period is best understood as a product of voluntary population movement.
The Economic Rationality of the Wage Differential
The dominant factor shaping this migration was income disparity. Contemporary records indicate that wages earned by Korean workers in Japan proper were approximately 50 to 70 percent higher than those for equivalent occupations on the Korean Peninsula, providing a powerful incentive for migration. Although Korean workers in Japan earned roughly half the wages of their Japanese counterparts, even this level represented — by the standards of the Korean domestic labor market — exceptionally high remuneration.
This dynamic is illustrated clearly by migration patterns of the era. When Korean representative Pak raised the issue in the Imperial Diet in 1933, the parliamentary record shows that approximately 50,000 Koreans were entering Japan annually, and that controlling this influx had become a policy challenge. The framing of “voluntary inflow requiring governmental restriction” is fundamentally incompatible with the narrative of “passive victims being forcibly taken.”
Job Advertisements in the Keijō Nippō: Evidence from Primary Sources
The Keijō Nippō (京城日報), the Government-General of Korea’s official newspaper published from 1906 to 1945, is held by the National Diet Library and is also accessible via the Internet Archive. Its pages contain multiple recruitment advertisements placed by mainland coal mines, construction firms, and factories seeking Korean laborers. These advertisements specified terms of employment — daily wages, provision of meals and lodging, and employer-paid travel costs — and detailed application procedures, demonstrating that prospective workers were offered an opportunity to choose. The very existence of recruitment through published advertisement is logically incompatible with forced abduction, and constitutes circumstantial evidence that, at least prior to 1939, labor mobilization retained the character of market-based migration.
2-2. Scrutinizing the Term “Forced Deportation”: A Legal Analysis
The range over which the term “forced deportation” (kyōsei renkō) can be applied with historical precision must be strictly bounded by reference to the legal instruments actually in force at the time.
Three Phases of Mobilization and Their Legal Character
| Period | System | Legal Character |
|---|---|---|
| September 1939 – January 1942 | Free Recruitment (direct recruitment by private firms) | Voluntary, contract-based |
| January 1942 – August 1944 | Government Mediation (kan-assen; administered by the Korean Labor Association) | Administrative intermediation |
| September 1944 – August 1945 | Direct application of the National Requisition Order (Kokumin Chōyō-rei) | Legally compulsory (conscription) |
This classification is grounded in official records documenting the operational reality of the relevant legislation, and aligns with figures submitted by the Japanese government in February 1962 at the Japan-Korea talks — figures jointly accepted by both governments. Those figures show: free recruitment phase, 148,549 persons; government mediation phase, approximately 320,000 persons; national requisition phase, approximately 200,000 persons; total 667,684 persons. The period during which legally compulsory “requisition” was actually enforced was limited to approximately eleven months before the end of the war, and further reduced to roughly seven months of practical transport capacity before ferry services between Shimonoseki and Busan became untenable in March 1945.
In other words, of the total mobilization of approximately 667,000 persons, the portion that qualifies, in the strict legal sense, as “state-compelled conscription” was limited in both duration and scale to a fraction of the whole. Applying the blanket label “forced deportation” to the entire mobilization, without regard to these distinctions, does not meet academic standards.
The National Requisition Order Was Universal Wartime Legislation Applying to All Japanese Subjects
The National Requisition Order (Imperial Ordinance No. 451 of 1939) was enacted as part of the general wartime national mobilization framework, targeting all subjects of the Japanese Empire; it was not discriminatory legislation designed specifically to target Koreans. It came into effect in Japan proper in July 1939, and by the end of the war the total number of persons conscripted — including Japanese — had reached 6.16 million. The fact that application to Korea was withheld until September 1944 itself means that Koreans were exempted from conscription for an extended period.
2-3. The Postwar Period of Disorder: The Fact of Illegal Entry
The Yoshida–MacArthur Letter (Estimated: Late August to Early September 1949)
Among the primary sources indispensable to any analysis of the postwar situation of Koreans in Japan is the letter addressed by Prime Minister Shigeru Yoshida to Supreme Commander for the Allied Powers General Douglas MacArthur (Location: MacArthur Memorial, Record Group 5, Box 3; Japanese translation in Rinjirō Sodei, ed., Yoshida Shigeru = MacArthur Ōfuku Shokanshū [1945–1951], Hōsei University Press, 2000, Part II, Item 122).
Written on official Cabinet letterhead, the letter contains the following passage:
“We are now pressed to find an early solution to the problem of the approximately one million Koreans residing in Japan, of whom nearly half are illegal entrants.”
The historical significance of this statement is substantial. In an official document addressed to the Supreme Commander of the Allied Powers in 1949, the highest-ranking official of the Japanese government explicitly recorded his assessment that approximately 500,000 of the one million Koreans then residing in Japan had entered the country illegally.
Why Did Those Who “Fled” Come to Japan?
The motivations of those who traveled to or re-entered Japan after the war’s end are documented across multiple sources:
- Escape from the violence of the Korean War (1950–1953)
- Flight from political persecution, including the Jeju April Third Incident of 1948
- Reunion with family members who had remained in Japan
- Japan’s continued relative economic stability compared to the Korean Peninsula
The very existence of these motivations is fundamentally at odds with the narrative of “enslaved victimhood.” Had Japan been, for these individuals, a place of exploitation and oppression, the end of the war should have produced a large-scale voluntary repatriation — and indeed, approximately 1.4 million people did return to the Korean Peninsula by the end of 1945. Yet the subsequent illegal re-entry of a significant number into Japan demonstrates that “remaining in Japan” represented, for those involved, a rational choice in both economic and security terms.
Testing Economic Rationality: The Logical Contradiction
Here lies the decisive logical contradiction embedded in the coercive narrative.
Premise A (the narrative’s claim): Koreans were forcibly abducted and transported to Japan, where they were subjected to slave-like treatment.
Observed fact: After the war’s end, large numbers remained in Japan voluntarily; substantial numbers subsequently sought illegal re-entry.
Logical implication: If Premise A were true, there would be no economic rationality to explain why people liberated by the war’s end would choose to remain — or actively seek to return — to the same country.
According to the basic rational-actor model in economics, people do not voluntarily return to a place from which they should be fleeing. The documented behavior of choosing to remain in or re-enter Japan constitutes behavioral evidence that the country was not, at least by the subjective assessment of those involved, a place to be escaped.
3. Methodology of Revisionism
3-1. Substitution of Terms
The most frequently observed operation in certain narratives is the wholesale replacement of terms, disregarding the diversity of mobilization forms:
- “Labor migration” (dekasegi) → “Forced entrapment” (renkō)
- “Recruitment” (boshū) → “Abduction” (rachi)
- “Government mediation” (kan-assen) → “Forced labor” (kyōsei rōdō)
As the legal classification above demonstrates, during the period from 1939 through August 1944, the form of administrative involvement evolved, but none of it constituted legal compulsion under the requisition ordinance. Describing the entirety of this period as “forced deportation” is, by reference to primary sources, factually incorrect.
3-2. The Illegitimacy of Comparative Claims
Some narratives employ rhetoric that places Japanese wartime mobilization on the same level as the Holocaust or American chattel slavery. This comparison does not withstand academic scrutiny.
American chattel slavery was characterized by race-based, permanent legal subordination; the treatment of persons as property; and a condition of hereditary servitude transferable across generations. The Holocaust was a state-organized mass extermination in which the annihilation of an ethnic group was set as a national objective. Japanese wartime labor mobilization, by contrast, was a component of a wartime labor regime imposed on the entire national population — including Japanese citizens — and was not directed toward the extermination of any ethnic group. Deliberately equating phenomena that are categorically distinct is not historical analysis; it is the destruction of historical context.
3-3. Excessive Reliance on Testimony and Neglect of Documentary Evidence
A salient methodological problem in narrative construction since the 1990s has been the tendency to prioritize “testimony” collected decades after the fact over verifiable primary sources, official records, and statistical data.
Testimony is an important element of historical research, but it cannot, standing alone, serve as definitive grounds for establishing historical fact. Memory transforms over time and is susceptible to social pressure and the influence of pre-existing narratives. Moreover, testimony collected within the institutional context of litigation or compensation claims is subject to incentive structures that may affect its historical neutrality.
By contrast, the Ministry of Health’s Labor Bureau survey “Status of Group Immigration of Koreans” (September 1945), Home Ministry Police Bureau statistics, contemporary parliamentary records, and diplomatic documents — including those held at the MacArthur Memorial — were recorded to meet the administrative needs of their time and were not produced to serve subsequent political objectives. The prioritization of primary sources over retrospective testimony is a foundational principle of historical methodology.
4. Global Impact
4-1. The Weaponization of Historical Information
The political instrumentalization of historical narrative has effects that extend well beyond bilateral diplomacy. Cases have been documented in which factually unsupported claims have been embedded as “established orthodoxy” in proceedings of United Nations human rights bodies and in the educational curricula of certain states. Once a narrative achieves the status of orthodoxy, the cost of displacing it vastly exceeds the cost of its initial propagation. This asymmetry confers a structural advantage on whichever party succeeds in shaping the narrative first.
4-2. Reputational Damage to Japan
The label of “slave state” inflicts direct damage on a nation’s soft power and brand value. Depriving successive generations of Japanese of the opportunity to understand their historical context accurately also affects the formation of national identity. Diplomatic pressure for apology and reparations premised on an inaccurate narrative obstructs fact-based dialogue and serves to politically revive issues legally resolved under the Treaty on Basic Relations between Japan and the Republic of Korea and the accompanying Claims Agreement of 1965.
4-3. Obstruction of a Forward-Looking Japan-Korea Relationship
The sustained circulation of narratives that prioritize emotionally charged victimhood over empirical fact structurally impedes the building of a forward-looking cooperative relationship between Japan and the Republic of Korea. The crux of the problem is not that the facts themselves are in dispute, but that the interpretation of facts and the definition of terms are being manipulated for political ends. As long as this manipulation persists, mutual understanding between the civil societies of the two countries cannot deepen.
5. Conclusion and Recommendations
5-1. Multilingual Digital Archiving of Primary Sources
At present, primary sources accessible in languages other than Japanese are severely lacking. Digitizing and making openly accessible — in Japanese, English, and Korean — the public records, statistics, and correspondence held by the National Diet Library, the Diplomatic Archives of the Ministry of Foreign Affairs, the MacArthur Memorial, and the National Archives of Japan is the most fundamental means of correcting the existing information asymmetry.
5-2. Sustained Dissemination of Empirically Grounded Academic Counterarguments
What can effectively counter political slogans is not equivalent political slogans, but the accumulation of peer-reviewable empirical research and evidence-based analysis. This requires submission of English-language papers to international academic journals, the presentation of factual evidence at international symposia, and collaboration with educational institutions to promote accurate historical understanding. It is not emotional rebuttal but cold, hard facts and data that carry the greatest persuasive weight with third parties — with the international community.
5-3. Strict Application of Universal Legal Norms
Regardless of historical background, current immigration and residency law constitutes a universal legal framework aligned with international standards; exceptional treatment premised on ethnic origin or migration history is inconsistent with the principle of equality before the law. Sensitivity to historical circumstances and strict enforcement of legal order are not mutually exclusive — indeed, ensuring the latter is the foundation of credibility for a state governed by the rule of law. Maintaining transparent, internationally compliant administration of immigration law is the most effective answer Japan can give to the international community.
Primary Sources Referenced
| Source | Issuing Authority | Date | Location |
|---|---|---|---|
| Survey on the Status of Group Immigration of Koreans (Chōsenjin Shūdan Iinyū Jōkyō-chō) | Ministry of Health, Labor Bureau | September 1945 | National Archives of Japan |
| Foreign Affairs Section Statistics, Home Ministry Police Bureau | Ministry of Home Affairs | Various years | National Archives of Japan |
| Number of Koreans in Group Immigration (submitted to Japan-Korea talks) | Ministry of Foreign Affairs of Japan | February 1962 | Diplomatic Archives, MOFA |
| Letter, Prime Minister Yoshida → General MacArthur | Office of the Prime Minister | Est. August–September 1949 | MacArthur Memorial (RG5, Box 3) |
| Keijō Nippō (microfilm reproductions) | Keijō Nippō Company | 1907–1945 | National Diet Library; Internet Archive |
| National Requisition Order (Imperial Ordinance No. 451, 1939) | Government of Japan | July 1939 | Official Gazette; National Archives |
| Agreement on the Settlement of Problems Concerning Property and Claims | Governments of Japan and Republic of Korea | June 1965 | MOFA public documents |
The citations and interpretations of primary sources contained in this report are grounded in academic empiricism and are not intended to advocate for any particular political position. The accurate presentation of fact is the precondition for sound historical understanding and productive international dialogue.