The Karumekin which was broken, chipped and chafed were increasing, having been circulated more than 90 years, and such Koban was mended in kin-za (an organization in charge of casting and appraising of gold during the Edo period) by adding gold.
流通は90年以上に亘る長期間であったため、折れ、欠け、磨耗による軽目金が次第に多くなり、このようなものは金座で足し金を行い修理が行われた。