I purchased a bag with coins from around the world. French, Mexican, Panama and more. This piece was in the group and I have no clue. Don't know if it's right side up . Let me know. Anyway, experts to this type please let me know. Is it a token? Thanks for info.
It's from Japan, a Tempo Tsuho coin, value 100 mon, issued c. 1835-1870. It's a bona fide coin, issued by the Japanese government and everything. Fairly common, not worth a huge amount, but still very cool- how many oval circulating coins do you see? Hope this helps.
And as for the piece being "OVAL", my first thought was it was a token. I've not seen many oval Japenese coins, cool piece and glad someone along the way didn't clean it.