Even in Shibuya where there are a lot of people, trash is conspicuously absent.

When I read this line it took me back to Jujutsu Kaisen Shibuya arc.

The government should place sanctions on people that litter and enforce the law with the police, maybe when people hear two or three persons have gone to jail for six months for trashing the environment the the general public will be force to behave well and dump their trash in the right place.