My IntegrationGPJS Staff Interviews

I never stop asking why war
Studying the
interplay of economy and
in the Greater East
Asia Co-Prosperity Sphere

Graduate School / Faculty of Arts and Letters
Tohoku University, Professor

ADACHI Hiroaki

Sharing in English about source materials essential for Japanese history studies, while integrating research methods from abroad

I have been a member of the International Graduate Program in Japanese Studies (GPJS) since March 2018, when we held symposiums at Ca’ Foscari University of Venice, Italy, and Ghent University, Belgium. In the following years, I have had multiple opportunities to exchange knowledge and experience with our foreign colleagues, for instance, as an instructor for the GPJS staff training program at Heidelberg University, Germany.

To give a more recent example, I presented at a mini-panel “The transmuting body of the long 1960s and its legacy: Art, Memories, Textbooks” during the 8th Annual Hasekura International Japanese Studies Symposium held at the Sapienza University of Rome, Italy. As a member of the Japanese Studies International Research Cluster, I was able to join forces with researchers from Sapienza University to conduct a comparative study of the 1960s in Italy and Japan.* My panel paper, "Japan's 'Long 1960s' as Seen in High School Textbooks,” elaborated on our findings.

My conversations and collaborations with foreign, mostly European, scholars made it crystal clear that some changes are long due in our field, that is, the history of modern and contemporary Japan. We must gain a good understanding of the differences between the state of research and methodology in Japan and elsewhere and then combine and integrate those different research traditions. For instance, there is a problem of accessibility: source materials on Japanese history are within the reach of Japanese researchers but not their foreign colleagues. This is doubly true for materials related to the history of modern and contemporary Japan: since massive amounts of new documents get opened to the public every year, even updating the information on available sources is a daunting task.

This is exactly why Japanese scholars should introduce locally available materials in English and, furthermore, deliver empirical research based on them. At the same time, it is necessary for us to absorb unique analytical angles and theoretical frameworks that are the forte of foreign researchers. It is true that contemporary Japanese historians will utilize publicly available materials to explore even the minutest matters. But at some point they started to eschew a broad historical perspective so often displayed by their foreign colleagues. I have come to believe that in order to develop the study of Japanese history in the global research environment, we need to understand the pros and cons of research within and outside Japan, merge those differing strands through dialogue and exchange, and perfect them into an approach distinguished by a broader outlook and deep understanding. The above experience and ideas undergird the key policy of the Center of Integrated Japanese Studies established in October 2023. The Center aims to promote “the integration of research methods, combining those that emphasize precise empirical findings with others that emphasize originality in theory and conceptual understanding” (Center Director Yanagihara Toshiaki).


* Our findings were published in the edited volume Revolutionary Times: A Comparative View of the Long 1960s in Japan and Italy released by the GPJS in 2022 (in the foreground).
Inspired by research collaboration with economic historians to study the Greater East Asia Co-Prosperity Sphere in its entirety.

As a researcher of modern and contemporary Japanese history, I have focused on the Greater East Asia Co-Prosperity Sphere (GEACPS), an attempt by the Japanese Empire to consolidate various East and Southeast Asian territories into an autarky with Japan as a center. The GEACPS was the theme of Professor Awaya Kentarō’s seminar at the Faculty of Arts, Rikkyo University. That seminar inspired me to explore Japan’s economic advancement into Southeast Asia before the Asia-Pacific War in my doctoral thesis and later start full-scale research on the GEACPS.

A turning point in my research was a collaboration with economic historians for a collected volume Southern Co-prosperity Sphere: Japanese Economic Domination of Southeast Asia during the Pacific War (Taga Shuppan, 1995). My experience in studying political history did not prepare me for the uncompromising exhaustiveness of their research: the statistical approach to historical events, the tendency to contemplate the phenomenon in its entirety instead of isolating one part, and the comprehensive use of all available sources. Our joint work made me notice how economy was utilized for political needs even as politics found itself at the mercy of economy. I also acquired a methodological stance which involved thorough accumulation and analysis of all available Japanese-language sources. This new approach also pushed me to extend my focus from Southeast to East Asia, look into interregional connections, and take all developments as interconnected parts of a larger system.

My investment in the topic of the GEACPS grew during a month-long stay at Heidelberg University in 2019. Conversations with non-Japanese researchers convinced me that it was high time someone created a holistic picture based on Japanese-language sources of how the Japanese side conceptualized the GEACPS and developed its policies in accordance with that vision. It took me over two years to publish a book The Greater East Asia Co-Prosperity Sphere: The Empire of Japan and Its Idea of Asian Domination (Chuokoron-Shinsha, 2022). As a next step, I intend to situate the GEACPS’ project of establishing economic self-sufficiency in the context of world history and further elucidate its distinguishing features through a comparative study of autarkic and colonial policies undertaken by the Japanese Empire and other countries.

Unraveling the causes and realities of war to confront the problems of contemporary society

This research originates in my own family, whose lives were warped by the war. We never discussed this directly, but my grandmother’s son died from a disease while fighting at the front. My father volunteered into the Navy at the age of seventeen, while my mother had to work under the labor mobilization. Both later regretted not getting a proper education. Conversations with my Grandma and parents made me question the nature of war and its causes. I wondered if looking deep into those questions might help us prevent future wars. This personal project led me to study the history of modern and contemporary Japan in general and the Greater East Asia Co-Prosperity Sphere in particular.

My research was also greatly inspired by my school teachers. Our history teacher in junior high school was keenly interested in the exchange between Japan and Korea. I decided to study the modern history of Japan after taking his elective class on the Japanese rule of Korea. The other mentor who influenced me greatly taught an elective seminar course on modern novel for senior students. We would read writers such as Noma Hiroshi, Dazai Osamu, Ōe Kenzaburō, and Kaikō Takeshi, and summarize and discuss their works in class. Through such discussions, I grew interested in the historical background of those novels. I had always liked castles and was quite fascinated with the Sengoku period, but under the influence of those teachers, my interest gradually shifted towards the history of Japanese wars and post-war periods. They made me ask the major question, ‘What is war?”, which I have been trying to answer ever since.

The GPJS aims to “tackle and break through the complex challenges of modern society” (Program Director Ono Koji), which include wars and conflicts that keep flaring up in various parts of the world. If Japan is to contribute to war prevention, the first step is to utilize its historical experience with the Asia–Pacific War and the Greater East Asia Co-Prosperity Sphere. Japan once inflicted terrible calamities within and beyond its borders — as a researcher of its history, I am resolved to continue examining the fundamental nature of war and the driving forces behind it.

Placing Japan in global history as a crucial historical actor

One of the graduate students in our Department of Japanese History is also enrolled in the GPJS. This student has always been an enthusiastic language learner eager to share their research results in English; now they are staying at Leiden University, Netherlands, enjoying the opportunity to perfect their English and study Dutch. They are also learning the European area studies perspective on Asia and Japan, another step in moving beyond history studies and taking a multidisciplinary approach to their own research project. Said project involves tracing the historical roots of emigration to the Philippines and Indonesia against prewar Japan’s economic advancement into the South Seas. Apparently, this young researcher was eager to join GPJS because through their study they hoped to uncover some hints instrumental in addressing the very contemporary issue of migration. As suggested by this example, the GPJS holds particular appeal for those wishing to conduct and share their research on the global level.

I often hear from European scholars in Japanese studies that Eurocentrism remains mainstream in English-speaking academia. As a Japanese historian, I have not experienced this bias myself, but other Japanese researchers seem to agree. If Eurocentrism is indeed a problem, we may find a hint at its possible solution in the following comment by the first GPJS program director, Professor Ozaki Akihiro: “Universal ideas associated with Europe are not, in fact, exclusively European in origin. The developments of human thought in ancient Greece, during the Renaissance, and later on have always been considerably influenced by Asia.” As Professor Emeritus in Art and Art History, he described the impact of ukiyo-e woodblock prints on modern paintings to illustrate his point. In sum, we can find traces of Japanese thinking even in ideas and views that have grown on European soil. From the point of view of history studies, Japan has been an important actor in world history, steering the course of events on the global level. The object of my interest, the Greater East Asia Co-Prosperity Sphere, was also the product of complex interactions and mutual influences that involved not only East and Southeast Asia, but also the UK, the United States, and other Western countries. By disentangling those connections, I intend to broaden our understanding of world history, or history on the global scale.

  • Graduated from the Department of History, College of Arts, Rikkyo University
    Completed the doctoral program in history at the Graduate School of Arts, Rikkyo University
  • Career:
    Teacher, Rikkyo Junior High School
    Teacher, Rikkyo Ikebukuro Junior and Senior High School
    Assistant Professor, Associate Professor, Graduate School of Arts and Letters, Tohoku University
    Professor, Graduate School of Arts and Letters, Tohoku University
    Head of Japanese Studies International Research Cluster, Tohoku University
    Vice Director of the Center for Integrated Japanese Studies, Tohoku University
  • Major Field of Research: History of Modern and Contemporary Japan
  • Tohoku University Researcher Profile