A big shift and dividing line happens as Japanese youth transition from Jr High to High School.

To get into high school, which is not mandatory altho 96% of kids go, you have to pass an exam. The tougher academic schools have a tougher exam. So kids start to get "sorted" at about age 15 or so. The kids that pass the test, go to the "good" school, are more likely to go to college, etc, etc.

The kids you see acting out, etc most likely knew very early that they weren't going to cut it as salarymen or conventional housewives and took another path.

One way to "rebel" in Japanese society is to purposefully not go along with the group, so some of these kids either don't belong or don't want to belong.

-JCH