AmazonJP clearly say "includes Japan original steelbook" in the item name and description.
the steelbook is like an external bonus for regular Blu or 4K digipack edition. AmazonJP removed the pic of steelbook. I don't know why.
I can't believe I missed this edition. I just thought it was just the Steelbook. Now I'm tempted with this to go with my German Godzilla statue from the original film, but I hate paying more than retail and don't really want to deal with a 3rd party in case something goes wrong and possible customs charges.