On June 8, South Korean President Lee Jae-myung expressed the view that a prudent approach should be taken regarding the conclusion of an Acquisition and Cross-Servicing Agreement (ACSA) between Japan’s Self-Defense Forces and the South Korean military. An ACSA is a framework that allows participating armed forces to provide each other with logistical support, such as fuel and ammunition. President Lee also acknowledged the need for such an agreement, while expressing concern about a possible shift toward greater confrontation in the security environment of East Asia. At the same time, he remarked that “it would be difficult for the agreement to be accepted in light of public sentiment.”

The "public sentiment" to which he referred is rooted in memories of Japan's colonial rule of Korea beginning in 1910, assimilation policies, labor and military mobilization under Japanese rule, and the loss of Japanese nationality by many Koreans following the entry into force of the San Francisco Peace Treaty in 1952. Today, relations between Japan and South Korea are arguably better than ever, both politically and at the private-sector level. Nevertheless, the weight of this “collective memory” remains considerable—so much so that the current president has stated that “these issues must one day be addressed if we are to build a truly genuine Japan–South Korea relationship.”

I came across this news just after reading the newly republished edition of Nagai Ana (The Long Cave) by Osamu Tezuka, released on June 2 by Hosei University Press. Originally published in 1970 and never included in Tezuka’s collected works, the story portrays the negative historical legacy between Japan and Korea through the life of a Korean resident in Japan who concealed his past and achieved success in postwar Japanese society. Against this backdrop, President Lee’s reference to “public sentiment” resonated deeply and prompted renewed reflection on the themes of history and migration.

Since the Meiji era (1868–1912), Japan has alternated between sending emigrants abroad and accepting migrants, depending on labor supply and demand at different points in time. The population, which stood at roughly 30 million at the end of the Edo period (~1868), grew rapidly as the country modernized. Faced with population pressures, the government encouraged emigration, sending more than one million people to South America, North America, mainland China, and the South Pacific islands. During World War II, labor shortages led to the mobilization of workers from Japan’s colonies. After the war, as large numbers of Japanese nationals returned from overseas territories, the government again promoted emigration, particularly to Latin America.

Today, Japan supplements its workforce through programs such as the Technical Intern Training Program, the Employment for Skill Development Program, and the Specified Skilled Worker system. Whether people are sent abroad or received from overseas, it is ultimately individuals who bear the fate of living as minorities in a foreign land. First published 56 years ago, Tezuka’s work continues to challenge us in the Reiwa era to think about the meaning of discrimination and coexistence.

Takashi Mizukoshi, the President
This Week’s Focus, June 7 – June 11, 2026