That thing I see on podiums and backdrops?
That all formal diplomatic letters are still sealed with to this very day, without exception.
Why would anyone here know this?
We've probably all seen media depicting a medieval king pressing a seal into wax, but it doesn't mean we're familiar with it as a modern legal or procedural thing. Japan has what I assume is the same thing: hanko, a personalized, carved stamp. It's always a subject of surprise and novelty for North Americans who go there to teach English.