I began writing the academic articles that formed the foundation of this book when I was stationed in Washington, DC while working for the Japanese Embassy (2018–2021). As a research base, I obtained a visiting scholar position at the Space Policy Institute in the Elliot School of International Affairs at George Washington University (gwu). My academic exchange partners naturally tended to be American and European experts, which was very useful in keeping abreast of international trends in this field. On the other hand, it was always difficult to obtain Japanese-language literature, especially since the covid-19 pandemic made it difficult for me to return to Japan, and I had to rely on many colleagues, friends, and family members.
I would also like to thank the many people who provided guidance and cooperation on the content of this book. Professor Hiroyuki Banzai of Waseda University (Tokyo) gave me warm and strong guidance and encouragement, and I learned from him the very strict attitude I should take as a researcher. I was also able to keep the big picture in mind thanks to the advice of Professor Akio Shimizu, Professor Takao Suami, and Professor Shuichi Furuya of the same university. The points made by Professor Henry Hertzfeld, who was my host faculty member at gwu, were always deep and sharp. I cannot forget the gratitude I owe to Professor Setsuko Aoki (Keio University (Tokyo)), a world-renowned authority on space law research, who warmly welcomed me into this world. Associate Professor Masayuki Hiromi (Kobe City University of Foreign Studies) was kind enough to provide many opportunities for online discussions.
In addition, because this book deals with a topic that is international law but is close to the interface with international politics and international relations, I am grateful to Professor Yuichi Hosoya (Keio University), Professor Dana Johnson (gwu), Professor Mitsuru Nishida (Nagasaki University), Professor Harukata Takenaka (National Graduate Institute for Policy Studies (Tokyo)), Associate Professor Azusa Uji (Kyoto University), and Dr. Quentin Verspieren (European Space Agency), who provided valuable advice and cooperation.
Further, I am grateful to the experts of the Japan Aerospace Exploration Agency (jaxa), including Ms. Motoko Mizuno (currently a member of the House of Councillors of Japan) and Dr. Masami Onoda for introducing me to many pioneers in the space field, who have greatly broadened my horizons. I am also indebted to many other experts, including Dr. Satohiro Akimoto, Dr. Ntorina Antoni, Mr. John Giles, Mr. Brian Israel, Dr. Akira Kato, Ms. Rei Kawashima, Dr. Masahiro Kurosaki, Dr. Peter Marquez, Dr. Kevin O’Connell,
Within the Japanese government, I received support from four generations of the Secretary-Generals of the National Space Policy Secretariat of the Cabinet Office: Mr. Shuzo Takada, Mr. Takehiko Matsuo, Mr. Yasuyuki Kasai, Mr. Jun Kazeki, and their bureaus. Many seniors and colleagues at the Ministry of Foreign Affairs, where my main office is located, also provided generous assistance in collecting literature and taking a fresh look at the book’s contents. However, the views expressed in this book are my own, and do not represent or infer the views of the Japanese government.
Finally, I would like to express my deepest gratitude to Professor Frans von der Dunk for finding my thesis and working hard to make it part of this prestigious series of Studies in Space Law. Also, Ms. Beth Derr and Marie Sheldon, who worked on this book at Brill, were very attentive in helping me publish my first monograph in English.
I would like to express my deepest gratitude to all those who helped me.