Japan, 1846 AD., Kōka era, Satsuma mint, 100 Mon (To Hyaku Sen or "Tempo Tsuho"), JNDA 135.3 C.

Japan, Kōka era (December 1844 - February 1848), Satsuma mint, Kagoshima prefecture, signed by mintmaster Hashimoto Mitsuji, produced ca. 1846 AD., general type cast 1835-1869,
100 Mon (To Hyaku Sen (Value 100 Coin) or "Tempo Tsuho") (ø 32,5-48,8 mm / 21,50 g), bronze (78% copper, 12% lead, and 10% tin, although this deteriorated as time went on), oval shape with a square center hole (broad hole) - the rim of the hole is broad, official weight 21,75 g., total mintage 484.804.054 (all mints and variations 1835-1869), axes medal alignment ↑↑ (0°), plain edge, countermarks on the edges on both sides, stamps of sakura (cherry blossom) of various shapes and sizes,
Obv.: 天 / 保 // 通 / 寶 , (Ten-Ho // Tsu-Ho) , vertical inscription above and below square center hole.
Rev.: 當 / 百// (mint mark) , "To Hyacku" = "value 100" , vertical inscription above square center hole, signature of the mint official (composed signature of mintmaster Hashimoto Mitsuji) below.
KM C 7 ; J 324 ; JNDA 135.3 C.

Over 100 varieties of the Tempo have been recorded, but most of the differences "are only perceptible to those who have made such matters a special study". Not only changes in the calligraphy, and differences in shape, but also differences in workmanship are criteria for attributions.
Official coins were cast using very fine sand from Bosho in Chiba which gave the coins a smooth field. Illegal mints used coarser sand, which resulted in a grainy field.

This type of "Tenpo Tsuho" coin is often termed "Glico Tenpo." Each Glico caramel box contained a prize, which came in a separate box attached atop the caramel box. It was something very similar to Cracker Jack prize, cheap collectible toy for children to enjoy. During the coin collecting craze of the 1950s, by collecting certain points, children could send away for a genuine Tenpo Tsuho. However, because of overwhelming demand for the coins, the genuine coins soon ran out. Glico company was forced to make imitation Tenpo Tsuho.