Those guides include resources covering Asian Americans in general, but they can be very useful to find other hidden resources specific to Japanese Americans by limiting search terms.
Nagata, S., & Millsap, W. The Japanese evacuation and the minority problem.
Beinecke Rare Book & Manuscript Library, Yale University Library
“Out of the Desert” exhibit by Cortney Sato. Website: https://outofthedesert.yale.edu/.
Yonekazu Satoda papers, photographs, and film (WA MSS S-2897) Box 1 - diary, 1942-1945, and materials related to US Army service, 1944-1947, Box 3 - correspondence and ephemera, circa 1943-circa 1948
Aito and Miyeko Takita Papers (WA MSS S-3211) Box 1, Box 2
Elizabeth Page Harris Papers (MS 771) Box 80, Box 81, Box 82 - correspondence with interned Japanese Americans and others and printed ephemera (including camp newspapers from Tulare, Gila River, and Heart Mountain) relating to Japanese American internment, 1942-1946
US War Relocation Authority, Poston, Arizona Relocation Center collection (MS 803) Box 1, Box 2, Box 3 - camp ephemera, yearbook, and scrapbooks, circa 1942-circa 1945, collected by Nathan Van Patten, a librarian at Stanford University
Charlotte B. DeForest Papers (Divinity Library Special Collections, RG 178), Series I, Box 2, folder 25: Letters of Kobe College alumnae affected by Japanese incarceration during WW II, circa 1940s.