In japanese culture, students WANT to learn. It's of great disgrace to do poorly in school. Unlike in the states, where yeu'll get yelled at maybe, or grounded, YEU GET DISOWNED.
There's a massive emphasis culturally on holding up a family name and providing honour to those they are related to. This's a massive change in mode of thought to our own on the west side of things, where we're more individualistic.
The short form is though, that schoolwork for the kids is treated like life and death, if they do bad, they make their parents look bad, and it's stressed culturally from birth that they HAVE to respect their parents to an intense degree, far moreso than we hold here.
DUe to that, they want to actually learn and get better.
In the states? Kids go to school because they have to, primarily, not because they want to.
Therein lies yeur biggest difference.