I found these looking through Japanese coins I had. They don't look like coins and hoping someone might know.
The first one is no Japanese piece that I'm aware of, but the other two look like pre-Meiji pieces, meaning that they were probably created before 1868. These two do technically qualify as coins. The second one is an Edo-period Tempo Tsuho from the 1840s. Most of these are common, but a few scarce varieties exist. This one appears to be the broad hole variety from 1846. I would have to see more detail on the third piece to date it properly, but it looks like a silver pre-Meiji Nanryo Gin piece. The dates are sometimes determined by the placement of the stars along the edges, but I would need to see a closer shot to determine the type and era.
Blowing up the photo, the one in the 400 yen 2x2 looks more like it should be a Isshu-gin (1 shu silver). Smaller and more common and starting from the Ansei era, but extending to the Meiji era. The mintage of them increased significantly after the arrival of Admiral Perry/opening of Japan so they are common. The Meiji ones are scarcer (a bit over 10% of the mintage from Ansei), and there are calligraphy differences to distinguish varieties. I can't see from your photo whether yours is Ansei or Meiji and after that I don't know the varieties. The silver to gold exchange ratio was such that there was a large scale exchange of silver to gold, which would then get more silver in the rest of the world (if I read the history right). Easy profit. Hartill's book uses the example of using 10 ounces of silver to buy an ounce of gold, then taking the gold back home and getting 15-16 ounces of silver back.
Sorry for the late response, but I got some closer pictures that may help out. I put the third piece through a 10x magnifier. I thought that it may help a little. The plastic that is holding the third piece says 150+ years old. Don't know how accurate that is though. Thanks!
