[girigiri]

Given the choice, I'd opt for schooling in Japan.

The arguments that
The main problem in Japan for kids is that they are not taught "people skills".

They just lack the know how to respond to any other culture than Japanese, in Japanese..

float like a sieve.

Japanese middle and high schools have a range of clubs available which allow for students to interact in meaningful ways. Japanese schools at least to some degree uphold the principle that others have rights too. They also uphold, at least to some degree, the idea that people should be allowed to take pride in their own accomplishments.

Where are you going to find a school that teaches people skills? Not here, that's a cert.

graduating university is "easy", and "everyone" graduates.
I'm assuming you mean that it is easy to graduate to university from High School. Yup - high school is hard grind. The hard part is graduating from High School, not entering a university. Even elevator schools have a minimum standard that you have to actually pass year 12.

More to the point, ripping a child of 12 or younger out of a familiar environment and dumping them in unfamiliar surroundings doesn't do a whole lot of good for that child's emotional development. (Unless the first environment is actively detrimental, that is.)