It's not chance
What is below is unusual, even in Japan, but high levels of dedication are not unusual. There seem to be more people like this in Japan than in the US. Is it the schools? The parents? The culture?
Probably it has to be put down to all three. Let's just be glad there are great things about America in all of these regards as well.
And if any piano teachers out there need to inspire your students.... she's 10, and says she learned this in six dedicated months.