Has anyone seen a 1989 year 64 proof set from the Japanese Showa era? Where can I find one, never seen it on eBay either.
I checked my Catalog of Japanese Coins and Notes which the Japan Numismatic Dealers Association publishes. I could not find a Showa 64 Proof Set. Rather there is a "Heiwa Gannen" (first year of Heiwa) set which was issued in 1989. Hirohito passed in January 1989. BTW there is NO Showa 64 50 yen piece according to the catalog. This might explain why there is no mint set as well. You can find a "Heiwa Gannen" mint set on E-Bay for about USD15.00. If you can speak Japanese I would reach out to one of two Japanese dealers in Tokyo: Taisei or Ginza Coins. You can find either on the Internet. Hope this helps.
No such mint set exist for Showa 64 in either UNC or proof. I believe no 100 yen was struck for Showa 64 as well. However I am certain there are unofficial Showa 64 sets floating around.