To be clear, when the OP wrote "Japan has bicycles with license plates", it is important to clarify the term "bicycle". It would more accurate to say "motorized bicycle". If you ride something that looks like a bicycle where you can power it only with a throttle button (no pedalling required), then it requires a license plate, at least in Tokyo. Explanation here: https://www.city.inagi.tokyo.jp/en/kurashi/zeikin/1002693/10...

Also, you can ask Google AI for more sources and info using this prompt:

    japan when does a bike require a license plate?