>>46801177I'd like to think post-settlement Kanto up to Johto became Japanocentric melting pots in the Pokémon world. Ancient Johto and Sinnoh definitely show signs of being 100% based on their real world equivalents while the modern ones in the games, lots of immigration and diluting took place. Some are less diluted than others.
Headcanon sure, but I would think someone like Misty or Jasmine would be "less Japanese" than Sabrina or Valerie.