Talk about a long lived series of coins! For over two hundred years, Japan issued 1 mon coins with the obverse inscription of 'Kan ei Tsu ho'. There are dozens if not scores of varieties, and it's beyond our scope to catalog them all. Suffice it to say that coins from before 1668 are known as old-, and coins from 1668 and after are known as new kanei tsuho. A great introduction to the different types can be found on this amazing website by Luke Roberts, associate professor at the University of California in Santa Barbara.
Prof. Roberts page tells us that Roxy's coin with the character 'Bun' on the reverse was struck in Kamedo, which I believe refers to a mint located in Kameido, a suburb of Tokyo. They were first struck in 1668, and are thus one of the very first 'new kanei tsuho' to be issued. The catalogs tell us that the production continued from 1668 until 1700. Values below are rough averages for all types:
worn: less than $1 US dollar approximate catalog value
average circulated: $2
well preserved: $5
almost uncirculated: $10
CoinQuest normally does not use the 'almost uncirculated' grade. The fact is that these coins are practically never found without wear, and never with full mint luster, which is required for a coin to be called 'fully uncirculated'.
Coins with severe damage are worth essentially zero. The values used above are catalog values - please see our Important Terminology page to learn how to interpret them and convert into actual buy- and sell values.