1 Mon 'Sendai-tsūhō' Bosen, small type

Sendai Domain received shogunal authorization to mint its own copper coinage in 1784, one of the few han granted this privilege during the Edo period. The Sendai-tsūhō was produced to address a chronic shortage of small-denomination currency in the Tōhoku region, where Edo-issued mon coinage circulated unevenly at best. The "small type" designation reflects a deliberate reduction in flan size from the domain's earlier issues — a cost-saving measure tied directly to rising copper procurement costs in the late 18th century.

Sendai's copper came primarily from mines in Mutsu Province, giving the domain unusual vertical control over its own monetary supply.