Dear Mr. Johnson,
Thank you for posting your request on History Hub!
We searched the Access to Archival Databases (AAD) and located the World War II Prisoners of the Japanese Data Files that includes 1 file for Arthur G. Christensen. We also located the Records of World War II Prisoners of War, 12/7/1941 - 11/19/1946 in the Records of the Office of the Provost Marshal General (Record Group 389) that includes 1 additional file for Arthur G. Christensen. This file lists the prisoner of war (POW/PW) camp where he was held as “Osaka Main Camp Chikko Osaka 34-135.” These records may be viewed online using AAD.
Next, we searched the National Archives Catalog and located the series Subject Files, 1942-1946 in Record Group 389 includes 1 file related to Chikko and 31 files related to Osaka. Most of these files are located in boxes 2129-2130 of the series, and box 2123 primarily contains records related to camp Fukuoka. Although the container numbers differ slightly from the online reference you found, it is possible that this is the series from the citation. The series Area Case Files, 1945-1948 in the Records of Allied Operational and Occupation Headquarters, World War II (Record Group 331) also contains some testimonies and affidavits and includes 1 file related to the "Taikoku Maru" and 12 files related to Osaka that may be relevant to your research. These records have not been digitized. For access to these and similar records, please contact the National Archives at College Park - Textual Reference (RDT2) at firstname.lastname@example.org.
We also located the Far East Name Index to the Series "Case Files, 1944-1949" in the Records of the Office of the Judge Advocate General (Record Group 153) that contains an entry for “Christensen, Major” on image 910 of this file that includes a reference to the “Tayaku Maru” that may be of interest to you. The index cards have been digitized and may be viewed online using the Catalog. The index relates to the series Case Files, 1944-1949 in Record Group 153 that contains a file for the case number (67-139) listed in the index card for “Christensen, Major” in box 1440. The case files have not been digitized. You may contact RDT2 for assistance with these records.
Plus, we located the series Diaries and Historical Narratives, 1940-1945 in the Records of the Adjutant General’s Office, 1917 - 1985 (Record Group 407) that contains a file with 1 reference to Christensen, Arthur G. and may be useful for your research. This file has been digitized and may be viewed online using the Catalog.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!