This system is far from perfect though. For example:

Forget the hanko home? Too bad, you’re sol.

Have an generic surname? Be ready to pay for an unique hanko, because the generic ones are sold at minimum for 100¥.

Live as an foreigner in japan? Prepare to write your signature again, again and again as the government official requires all the signatures to look exactly the same.

It’s also easily copyable if you know how the other person’s hanko looks like.

I’m just hoping japanese would move into hand written / electronic authentications. They are much harder to fake and you are not restricted by a small item which you may not always have with you.