1 Mon 'Tenseigenpō' Regular Script

Nagasaki occupied a singular position in Tokugawa Japan as the sole port legally open to foreign trade, and its civic administration was granted the right to produce local coinage partly to facilitate commerce at the Dejima trading post. The Tenseigenpō series was cast — not struck — using ceramic molds in the traditional Chinese fashion, a method the Dutch and Chinese merchants operating through Nagasaki would have recognized immediately.

The regular script designation distinguishes this type from cursive-script variants within the same emission period, a difference meaningful to specialists and largely invisible to the merchants who spent them.