50 Mon 'Doshū Zenisatsu'

The Tosa Domain issued its own paper currency during the chaotic final years of the Tokugawa shogunate, when dozens of feudal domains printed hansatsu — domain notes — backed by little more than local authority. Tosa's "Doshū Zenisatsu" translates roughly as "provincial copper-coin notes," the denomination expressed in mon, the copper cash unit, at a moment when the metal itself was in short supply and increasingly worthless.

Tosa is better remembered for producing the Meiji Restoration's most aggressive architects — Sakamoto Ryōma among them — than for its monetary policy. These notes were rendered obsolete almost immediately by the new government's currency unification push beginning in 1868.