Quite certain that these don't appear very often.
First up is a square looking coin from Sendai Prefecture. Cast in iron - has an interesting cud at the bottom. Not rare or any sort but thought the cud makes it different.

Next up is an interesting silver "coin" from Akita Prefecture, made around 1863. It's a hammered silver "plate" - thinly beaten and marked as 4 monme 6 bu. This coin did not last long as in 1870, uniform coinage appeared through the nation and in 1871, the yen is declared as the national currency. I'm certain a lot were melted down.

Lastly is a gold coin - never had a gold coin from Japan and found this in a reasonable price. Struck in 1871 - it's a really tiny coin.

Guess that's all for now - something different for a change?