For the trace of additional gold at the middle of the bottom, it is considered that craftsmen added some gold to the past current coin which has been called Yuzuriha Kin (the shape and the period in which it was minted are unknown) to adjust its weight.
中央下部に埋め金があり、譲葉金などの判金に足し金して量目を調整したものと考えられる。