Seventy years after the fact, the death of Sadanori Shimoyama on July 5, 1949, remains a mystery, officially unexplained. In Japan, hundreds of books and thousands of articles have attempted to solve the mystery. Novels, manga, documentaries, plays, and a film have also been based on the events of that night. At one time, it would have been no exaggeration to have compared the domestic political and cultural importance of the incident to the assassination of President John F. Kennedy, such was the level of public interest, the volume of publications, and proliferation of theories and conspiracies. However, as far as I am aware, the only substantial English-language accounts are to be found in Conspiracy at Matsukawa by Chalmers Johnson and Shocking Crimes of Postwar Japan by Mark Schreiber. The case also plays a fictionalized role in Osamu Tezuka’s manga Ayako, which has been translated into English.

The case was widely reported in the English-language press of the day: the Mainichi, Nippon Times, and Pacific Stars and Stripes. These newspapers, along with the Japanese-language Asahi, Mainichi, Yomiuri, and Tokyo Times, have all been invaluable sources of information (and misinformation).

The GHQ/SCAP record of the case – including crime-scene photographs, hand-drawn maps, internal memorandums, and copies of the notebooks of the Public Safety Division – are available in the GHQ/SCAP Records (RG 331, National Archives and Records Service), Box 292, Shimoyama Case – Crime, July 1949–January 1950, and these files can be accessed digitally at the National Diet Library, Tokyo.

A lot of material pertaining to Japanese war criminals, nationalist groups, and secret societies in postwar Japan has been declassified and can be accessed via the Library tab on the Central Intelligence Agency’s own website. However, the sections for Japan in the weekly intelligence summaries provided by the Office of Reports and Estimates, CIA Far East/Pacific Branch remain redacted for the period around the death of Sadanori Shimoyama. And for only that period.

In the following bibliography, I have omitted texts already listed in Tokyo Year Zero and Occupied City.

Ayako by Osamu Tezuka, translated by Mari Morimoto (Vertical 2010, 2013)

Black Blizzard by Yoshihiro Tatsumi (Drawn and Quarterly, 2010)

Blum-san! by Robert S. Greene (Jupitor/RSG, 1998)

Bōsatsu Shimoyama Jiken by Yada Kimio (Kōdansha, 1963) and the film of the same name, directed by Kei Kumai (1981).

Chronicles of My Life by Donald Keene (Columbia, 2008)

Conspiracy at Matsukawa by Chalmers Johnson (University of California Press, 1972)

Genji Days by Edward G. Seidensticker (Kodansha International, 1977)

Himitsu no Fairu: CIA no Tainichi Kōsaku by Haruna Mikio (Kyōdō Tsūshinsha, 2000)

Hōmurareta Natsu: Tsuiseki Shimoyama Jiken by Moronaga Yūji (Asahi Shimbunsha, 2002)

In the Realm of a Dying Emperor by Norma Field (Vintage, 1993)

Inside GHQ: The Allied Occupation of Japan by Takemae Eiji, translated and adapted from the Japanese by Robert Rickerts and Sebastian Swann (Continuum, 2002)

Japan Is a Circle by Kenichi Yoshida (Paul Norbury, 1975)

Japan Journals 1947–2004 by Donald Richie, ed. Leza Lowitz (Stone Bridge Press, 2005)

Jungle and Other Tales: True Stories of Historic Counterintelligence Operations by Duval A. Edwards (Wheatmark, 2008)

Keiji Ichidai: Hiratsuka Hachibei Kikigaki by Sasaki Yoshinobu (Nisshin Hōdō, 1975)

Kuroi Shio by Yasushi Inoue (Bungeishunjū Shinsha, 1950)

Legacy of Ashes: The History of the CIA by Tim Weiner (Penguin, 2008)

MacArthur no Nihon by Shūkan Shinchō Henshūbu (Shinchōsha, 1970)

MacArthur no 2000-nichi by Sodei Rinjirō (Chūō Kōronsha, 1974)

Nisei Linguists: Japanese Americans in the Military Intelligence Service During World War II by James C. McNaughton (Department of the Army, 2007)

Remaking Japan: The American Occupation as New Deal by Theodore Cohen, ed. Herbert Passim (The Free Press, 1987)

Saishō Onzōshi Hinkyūsu by Yoshida Ken’ichi (Bungeishunjū Shinsha, 1954)

Sakuragichō Nikki: Kokutetsu o Meguru Senryō Hiwa by Yamakawa Sanpei (Surugadai Shobō, 1952)

Senryō-ka Nippon by Handō Kazutoshi, Takeuchi Shūji, Hosaka Masayasu, and Matsumoto Ken’ichi (Chikuma Bunko, 2012)

Senryō Sengoshi by Takemae Eiji (Iwanami Shoten, 1992)

Shima Hideo no Sekai Ryokō 1936–1937 by Shima Takashi and Takahashi Dankichi (Gijutsu Hyōronsha, 2009)

Shimoyama Jiken by Mori Tatsuya (Shinchōsha, 2004)

Shimoyama Jiken: Saigo no Shōgen by Shibata Tetsutaka (Shōdensha, 2005)

Shimoyama Jiken Zengo by Suzuki Ichizō (Aki Shobō, 1981)

“Shimoyama Sōsai Bōsatsuron” in Nihon no Kuroi Kiri by Matsumoto Seichō (Bungeishunjū Shinsha, 1960)

Shimoyama Sōsai no Tsuioku (Shimoyama Sadanori Shi Kinen Jigyōkai, 1951)

Shinpan: Shimoyama Jiken Zenkenkyū by Satō Hajime (Impact Shuppankai, 2009)

Shiryō; Shimoyama Jiken, ed. Shimoyama Jiken Kenkyūkai (Misuzu Shobō, 1969)

Showa: A History of Japan by Shigeru Mizuki, translated by Zack Davisson, four volumes (Drawn and Quarterly, 2013–15)

Tales of the Spring Rain by Ueda Akinari, translated by Barry Jackman (University of Tokyo Press, 1975)

The American Occupation of Japan by Michael Schaller (Oxford University Press, 1985)

The Clandestine Cold War in Asia, 1945–65, ed. Richard J. Aldrich, Gary D. Rawnsley, and Ming-Yeh T. Rawnsley (Frank Cass, 2000)

The Human Face of Industrial Conflict in Post-War Japan, ed. Hirosuke Kawanishi (Kegan Paul International, 1999)

The Yoshida Memoirs by Shigeru Yoshida, translated by Kenichi Yoshida (The Riverside Press, 1962)

This Country, Japan by Edward Seidensticker (Kodansha International, 1984)

This Outcast Generation and Luminous Moss by Taijun Takeda, translated by Yusaburo Shibuya and Sanford Goldstein (Charles E. Tuttle, 1967)

Tokyo Central: A Memoir by Edward Seidensticker (University of Washington Press, 2002)

Wana by Natsubori Masamoto (Kōbunsha, 1960)

Yanaka, Hana to Bochi by E. G. Seidensticker (Misuzu Shobō, 2008)

Yonimo Fushigina Monogatari by Uno Kōji (Kadokawa Shoten, 1955)

Yumeoibitoyo: Saitō Shigeo Shuzai Nōto by Saitō Shigeo (Tsukiji Shokan, 1989)