Dear Tsubasa Okada,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the series Central Decimal Files, 1910-1963 and its corresponding Name Index, 1910-1973 in the General Records of the Department of State (Record Group 59) that may contain the memorandum you are seeking. We also located the series Briefing Books and Reference Material Relating to Japan, 1949-1957 (covering 1943-1957) in Record Group 59 that includes 7 files related to policy toward Japan that may be useful. These records have not been digitized. Please contact the National Archives at College Park - Textual Reference (RDT2) at firstname.lastname@example.org for access to these records.
Next, we located the series Sherwood Collection of Hopkins Papers, 1933-1945 in the Harry L. Hopkins Papers (Collection FDR-HOPKIN) that contains the file Book 9 - Policy Toward Japan that may be relevant to your research. These records have not been digitized. Please contact the Franklin D. Roosevelt Library (LP-FDR) at email@example.com for more information about these and similar records.
Due to the continued impact of COVID-19, you may experience a delay in receiving an initial acknowledgment as well as a substantive response to your reference request from RDT2 and LP-FDR. We apologize for this inconvenience and appreciate your understanding and patience as we balance mission-critical work and the safety of our staff during the pandemic. Please check NARA’s web page about COVID-19 updates for the latest information.
Please note that it is the policy of the National Archives for employees not to sign documents stating that particular records are not copyrighted since government records are in the public domain. For other materials, it is the user's responsibility to identify the copyright owner and to obtain all necessary clearances before using the records for purposes in excess of "fair use."
Most government records are in the public domain, however, some records in NARA’s custody may have donor, copyright, or other restrictions. If the records have been described in the National Archives Catalog, use restrictions will be noted in the individual descriptions.
The copyright law of the United States (Title 17, United States Code) governs the making of photocopies or other reproductions of copyrighted material. Under certain conditions specified in the law, libraries and archives are authorized to furnish a photocopy or other reproduction. One of these specific conditions is that the photocopy or reproduction is not to be "used for any purpose other than private study, scholarship, or research." If a user makes a request for, or later uses a photocopy or reproduction for purposes in excess of "fair use," that user may be liable for copyright infringement.
If you decide to use a document in your publication, the National Archives requests that you cite it properly following the guidelines in General Information Leaflet No. 17 on NARA’s website.
Finally, since Reischauer was employed at Harvard University when he drafted the memorandum, and since they have a collection of the Papers of Edwin O. Reischauer, we suggest that you contact them directly for further assistance.
We hope this is helpful. Best of luck with your research!
[Some information provided by Cathleen Brennan, Subject Matter Expert.]