I made a film roll keychain with a 5 yen coin. The 5 yen coin is a perfect fit for old Japanese film camera battery compartments. Plus it is lucky too. If you would like one, I will make one just for you. Check out the stuff page. It is it very limited due to my time and the number of used film rolls I have. The make of the film is not guaranteed, due to what I have in my bag of tricks.
My oldest son, now 32, learned Japanese in high school. Turns out he was born to speak the language — it came to him with such ease, and he spoke it so fluidly. He spent the summer after he graduated traveling around Japan, couch-surfing at the homes of friends he had made online. When he came back, he gave me a 5-yen coin for luck, and I’ve had it on my keychain ever since. That was 2004!
https://www.flickr.com/photos/mobilene/39965432754
They are perfect, with the little hole. They are thrown into shrine “wish” pots things.