Others were lucky to return home after the war, but the dreams of the daily brutalities of their days at Fukuoka 17 would never leave them.
The camp was one of dozens scattered across Japan, which held British, American, Dutch and Australian prisoners of war.
[citation needed] Mitsui specialized in the collection and study of postage stamps and postal history of Japan.
His numerous books include: Sekai gunji yubin gaiyo, written in 1939 in collaboration with Professor Yukio Masui of Keio University, and which translates to "Outline of the Military Postal Systems of the World."
In 1964 Mitsui donated the very important original sketches and final designs of stamps executed by Kasori Teizo from 1923 to 1952 to the Smithsonian Institution in Washington, D.C. Mitsui's extensive collections of Japanese and worldwide stamps were donated to the Communications Museum in Tokyo when he died.