Well, unless the US coins are miniatures, your piece is way too large for a genuine silver 1 yen. And there are multiple signs of casting (the originals were not cast). And the lettering of "ONE YEN" looks completely wrong. So I say that this is extremely fake, and thus worth nothing. (Almost certainly not really silver either.) Sorry about that.
So I check around the internet for a design like the coin on mine and couldn't find a single one with those 2 dragons so that was a huge red flag. Thank you to everyone who posted. Saved me a lot of time trying to figure this coin out.
