Originally Posted by
5khours
1. Foreigners are required to carry a gaijin card or passport at all times.
2. That said, I'm not sure police have a right to randomly check passports.
3. I've been asked for a passport a couple of times and when I asked if it was "gimu" (mandatory) that I show the passport, they said no.
Same here. ID checks by police are usually "shokumu shitsumon" (which means something like "on-duty inquiries") and compliance is optional. The cop will explain this to you if you ask them politely.