In most countries you can get what is called a notarized or certified "true copy" of identifying documents (passports being one of them). The intent is for you to submit them with applications so you don't have to submit the original copy. Now how you get a true copy depends on the country. Canadian passports for example can only have true copies made by their embassy or immigrations offices.

Note that this doesn't include your passport stamp pages but Japan hasn't issued passport stamps for several years now and they just look up your passport in a registry instead. So for that purpose, a true copy should be effectively the same thing.

That's where it comes down to what is essentially a technicality but given they carry an embossed seal and signature with the words "TRUE COPY" on them, they look very official and officials are very rarely going to push back on it even if whether they are to be treated as a full substitute for a passport (for identification purposes) is technically a grey area.