Seeking records about Umajiro & Yoshio Fred Imanishi

Umajiro Imanishi's naturalization petition should give you enough information about the family to begin your research.

There is quite a bit of information about the family in Washington and Idaho (internment camp during WWII) on both Ancestry.com (a paid research site) and familysearch.org (free site, just sign up for a password & username)

This obituary of Yoshio's aunt gives the names of his maternal grandmother and other relatives.  from Seattle Times 23 May 1956 p. 55

Dear Mr. Imanishi,

Thank you for posting your request on History Hub!

We searched the National Archives Catalog and located the series titled World War II Japanese Internee Cards, 1941 - 1947 in the General Records of the Department of Justice (Record Group 60) that includes a Japanese Internee Card for Umajiro Imanishi. We also located a series titled Class 146-13 (Alien Enemy) Litigation Case Files and Enclosures, 1938 - 1962 in Record Group 60 that may contain files on Umajiro Imanishi and Yoshio Fred Imanishi. To view the card and to request a search of the DOJ records, please contact the National Archives at College Park - Textual Reference (RDT2)  via email at archives2reference@nara.gov.

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.

In addition, we searched the Access to Archival Databases (AAD) and located the Records About Japanese Americans Relocated During World War II for 1942-1946 (also known as the [Japanese-American Internee Data File, 1942-1946] in Record Group 210 that includes records for Yoshio Imanishi and Shigeko Imanishi in the database.  We were unable to locate a record for Umajiro Imanishi.  If you wish to search the database further, please review Search the Database of Japanese American Evacuees (Record Group 210).

For more information, please consult NARA’s web pages on the War Relocation Authority and Japanese Internment records.

In addition to the information given by the previous poster, we suggest that you review NARA’s Resources for Genealogists, as well as the FamilySearch Research wiki for Washington State Genealogy.  In addition, the document Suggestions and Advice for Family History Researchers  may be useful. 

We hope this is helpful. Best of luck with your family research!