re: Tokyo, Shanghai, Osaka……why is that?

Their criminal code: Japan's drug laws are extremely harsh against foreigners & a foreigner arrested can be held without access to legal council for several mths. For citizens, its drug laws are fairly moderate, enforced but not harsh. But according to my Japanese d-in-law, arrests & subsequent prosecutions are the norm. A rap sheet with no consequences, to the extent it's common here, just doesn't exist there.