This note was authorized and produced in the final months of the Pacific War, when Japan's printing infrastructure was under severe strain and material shortages forced compromises across the entire currency series. The 4th type designation reflects successive redesigns driven not by aesthetic preference but by wartime production constraints — paper quality, ink availability, and plate wear all contributed to the iterative changes across the type sequence.
Postwar Allied Occupation authorities declared all Bank of Japan notes issued before the 1946 monetary reform legal tender through the transition, but serial tracking was poor enough that inflation-era hoarding and destruction make circulated survivors of this type considerably more common than uncirculated ones.
This note was authorized and produced in the final months of the Pacific War, when Japan's printing infrastructure was under severe strain and material shortages forced compromises across the entire currency series. The 4th type designation reflects successive redesigns driven not by aesthetic preference but by wartime production constraints — paper quality, ink availability, and plate wear all contributed to the iterative changes across the type sequence.
Postwar Allied Occupation authorities declared all Bank of Japan notes issued before the 1946 monetary reform legal tender through the transition, but serial tracking was poor enough that inflation-era hoarding and destruction make circulated survivors of this type considerably more common than uncirculated ones.