Toward the end of the Edo era (1600-1868), a carpenter living in Shimane Prefecture obtained an abacus made by a specialist from Hiroshima. Using this abacus as a model, he made his own from locally sourced oak, Japanese apricot and smoked bamboo (susudake).
Later, craftsmen from the district of Yokota-cho perfected a hand lathe for making abacus beads, which substantially increased production and created the foundation for today's small craft industry. The abacuses produced here are of such high quality that the name Unshu is practically synonymous with abacuses.

The most important element of an abacus is the beads, which should move freely and produce a clear click when they strike the frame or another bead. Careful attention is paid to the finish of the bamboo shafts and the holes of the beads. Unshu abacuses are characterized by how they improve in quality the longer they are used.