1 Mon 'Kan'eitsūhō' Old type

Kan'ei Tsūhō production began in 1636 across multiple mints simultaneously — an unusual decentralized approach that reflected the Shogunate's need to flood the economy with reliable copper coinage after decades of monetary fragmentation. The "old type" designation distinguishes these early issues from the vast wave of provincial and domain mint productions authorized later in the century, when output expanded so dramatically that the coin remained in official circulation into the Meiji period — over two hundred years after this first striking.