[Nyororin]

You must have your ID card or passport on you at all times, and you must present it when asked...
Other than that, you`re on the same legal standing as a Japanese citizen. Which can be good or bad depending on how you look at it.

I`ve been here for 10 years now and have never once been stopped. In fact, a recent event of interest; I spoke to a police officer for the FIRST time the other day when one came around to get emergency contact information from residents so they could attempt to notify relatives if something horrible happened. (A new police box was built and opened very recently.) Nothing weird happened, and I gave him the family home`s contact info. And then he went next door and asked them in the exact same way.