Japan is culturally very different. Every Japanese person is taught at school how to act in society. Cultural values are instilled there. In the west we believe that parents should have the last say on how to bring up children. In Japan, teachers have the last say. Teachers go to students' homes to make sure it is an acceptable environment for the student. If it is not, parents are required to take classes on how to be better parents. I can't tell you the number of times I've seen teachers calling in parents and yelling at them for hours until the parents, sobbing, promise to improve. One of my students was caught smoking and since the father was a smoker he was called into school. The vice principal blamed the father for the student's behaviour and insisted that the father never again smoke at home. The father agreed (and you know the home room teacher is going to go over to the house to make sure the agreement is kept).

That's why people don't litter here. For a test, I once left my change in the drink machine by the school -- a drink machine used by all the students. The change was still there 2 weeks later! I think the only reason it eventually was removed was because the company that restocked the machines took it. Probably only because they realised that it was an inconvenience for everyone having to sort out their correct change.

You just can't tell a city of millions of people to act like that ;-). It's a completely different culture and a completely different set of values.

A city can’t take any steps to make its people Japanese. Japan is a behavioral outlier, so the techniques it uses are not applicable to the rest of the population.