National Diet Library of Japan (NDL) announces that the maps of Taiwan created during the Japanese colonization period are now available on their site.
The Government Documents and Maps Department in Hamilton Library has some historical maps of China, Japan, and Russia.
Geographical Research Maps of China 1917
https://guides.library.manoa.hawaii.edu/special-collections/geographical-research-in-china-1917
Because of Okinawa’s proximity to Taiwan and Fujian Province in China, the maps might be of interest to some researchers.
Also, researchers might find the newly acquired book titled “Okinawa sekimin” no Taiwan hikiage shōgenshū (= 『「沖縄籍民」の台湾引揚げ証言・資料集』)(Okinawa: University of the Ryukyus, 2018). Roughly translated, “Interviews of Okinawans who lived but left Taiwan after the WWII.”