cars (Japanese Domestic Market) don't have standard 17 digit VUN numbers like USA/CAN/EU. There is an ISO standard for VIN numbers, but a lot of countries don't follow it.
JDM cars have a chassis code and a frame code. One of the places to find the plate with this info is on the door jamb of the left passenger door. Some brands give plant number and color number too.
So VIN lookup websites won't work with JDM cars. You could get basic info from some websites on the chassis code if you Google search for "JDM chassis code lookup." https://www.japan-partner.com/check-man ... e-year.php
2nd is that the VIN is not ISO standard for Grey market cars even though it's still 17 digits. Those are cars sold brand new outside USA/CAN/EU. The VIN lookup websites still won't work for cars bought new from local stealerships. You can still some basic info if you search as above.