Shōwa 5 Sen

The Shōwa 5 Sen coin switched to aluminum bronze in 1940, a wartime measure to stretch scarce copper supplies amid Japan's escalating conflicts.

That change reflected broader economic strains, with the Imperial Japanese government adapting coinage to support a faltering supply chain. The coin's design remained simple: a chrysanthemum crest on the obverse, the denomination on the reverse, all struck at the Osaka Mint. Records from that era are spotty; exact mintage figures for 1940 vanished in postwar chaos.

Variations exist due to wear and minor die differences, but it's not the rarity some claim. If you handle one, note the lightweight feel—aluminum bronze made it feel almost insubstantial, like carrying a whisper of prewar prosperity.