The beads you show are among the most-common and fairly available commercial decorated Japanese glass beads--that I refer to as "beach-ball" pseudo-millefiori work. I think of these as "parti-colored" rather than "floral."

Although you could probably find them in Japan, they would be easier to find online at eBay or Etsy (where they will probably be called "millefiori" by sellers who don't know better).

Here ;s a dialogue from 2017, that includes some discussion of them from 2009:

http://beadcollector.net/cgi-bin/anyboard.cgi?fvp=/openforum/&cmd=iYz&aK=3554075&iZz=3554075&gV=0&kQz=&aO=1&iWz=0

I hope you enjoy Japan! Jamey