I dunno. Given that those coins stopped being minted in 1897, it'd probably be worth quite a lot across the barrier to a collector, and the fact that it's made of silver makes it no slouch in Gensokyo, either.
Is it your NEW YEAR's gift for me?Thank you! ♡1 yen
Early 1 yen silver coin
Commentary:
"Flan-chan, hold out your hand.
One yen is a large amount of money at Gensoukyou. So use it wisely, okay? Ufufu!"