In Boku no Hero Academia, we know the world is not limited to only Japan; there are America and other countries as stated especially in the BNHA: Two Heroes movie. But why are the known top 10 heroes (probably all the best heroes) Japanese? Endeavor, Jeanist, Edgeshot, etc. are all from Japan, even All Might (although he's been in the USA doing hero work).
Is there another top hero that is actually not Japanese or not from Japan? Or is it just that Kohei Horikoshi makes Japan so much stronger in this series?