10 Sen - Shōwa Pattern, plain hole obverse

This is a pattern piece, not a circulation strike — the Japan Mint was actively experimenting with holed coinage designs throughout the early Shōwa period as part of a broader effort to rationalize the subsidiary coinage system. The "plain hole obverse" designation distinguishes it from companion patterns where the hole was surrounded by ornamental detail, suggesting the mint was testing whether a cleaner, unadorned perforation would perform better in vending and counting machinery then being introduced in urban Japan.

Nickel was abandoned for Japanese coinage entirely by 1938, replaced first by aluminum bronze and then by aluminum alone as military procurement consumed strategic metals ahead of the Second Sino-Japanese War.