Shunaka / 1/2 Shu 'Kōshū Shunaka Kin' Maru-Shunaka

Kai Province — the mountainous domain that would become modern Yamanashi Prefecture — operated one of Japan's most active regional gold-working traditions, fed directly by the Kōshū goldfields that Takeda Shingen had developed aggressively in the sixteenth century. By the time this piece was struck in the mid-Edo period, those mines were under Tokugawa administration, but local minting conventions persisted. The maru-shunaka form — essentially a small disc rather than the elongated tanzaku shape of mainstream Edo coinage — reflects a distinctly provincial approach to fractional gold that the central mint in Edo never fully standardized away.