My two sons one year ago started to collect every kind of crown cap. They started for fun. It is a play for them, but through the caps they started to know different languages, countries, flags, products. At the moment they have got about 250 different caps, all picked form the ground.
So, as they do not have got any Japanese crown cap, would you like to be so kind to send them some, just to encourage them to proceed in the collection, or to form a group of duplicates for further exchanges?
What a fun for them: washing the caps, then dividing them for colour, then for product, etc. Some caps are very elegant: there are good designers in Japan.