Yeah sure they can try to make that culture easier to understand through the game, but it's obvious that people will be more interested in something they grew up with. For example there is a really famous book here in Brazil named Sitio do pica-pau amarelo and it has several creatures from brazilian culture like Saci Perere, Mula sem cabeça e Cuca. Do you think people would rather read that book translated or a Harry potter book that has creatures that everyone knows like witches and fairies?
This game will certainly be popular, but if this game is supposed to have the same appeal as Pokémon once had outside Japan then it would have to be popular with kids from all types and cultures. (P.s: i am not saying you said that yokai watch will have the same appeal, i'm talking to the ppl who said it would kill pokemon)