There is a lot of confusion about some bead origins—between whether they are Japanese, Czech, or something else--as discussed in this link.

Consequently, nearly any site that I could advise (particularly at eBay or Etsy) might purport beads are "Japanese" when possibly that's a mistake (!). Bead sellers are notorious for not imparting accurate information. I write to sellers almost daily to correct mistaken identifications.

Of course, if you find beads that still have a "Made in Japan" tag on them, that would most-expectedly be accurate.

JDA.