These photos are from the auction. It is an:
Antique 1835 - 1870 Japan Large 100 Mon Coin (TEMPO TSUHO) Coin, model after the Koban gold coin said to be the shape of the Topview Ranchu.
From:
Bunsei and Tenpo recoinages
The Tokugawa Shogunate government carried out the Bunsei and Tenpo recoinages in 1818 and 1832, respectively, to debase the gold and silver coins in order to compensate for fiscal deficits.Official exchange rate was set at 1 ryo of gold = 60 monme of silver = 6,500 mon of copper.
The recoinages, however, caused confusion in the monetary system and increased commodity prices. The government also minted Tenpo Tsuho Hyakumon (100 mon)-sen and Tenpo Goryo (5 rho)-ban coins to cover fiscal deficits. The Tenpo Tsuho 100-mon-sen coins (1835) were minted in large numbers; however, the amount of material used for the mintage of each of these coins was almost the same as that used in five and a half Kan’ei Tsuho 1-mon-sen coins, which caused chronic rises in commodity prices. The amount of gold contained in one Tenpo 5-ryo-ban (1837) coin was equivalent to the total amount of gold contained in four and a half of the 1-ryo Tenpo Koban gold coins. This new, low-quality coin was badly received among the people, and the mintage was soon suspended.
Image from: http://www.lioncoins.com/jpegs/100MonTT.jpg
