I'm heavily tattooed, and I have many friends and customers who are tattoo artists. I know many tattoo artists from around the world, including Japan. Let me share with you an interesting story a Japanese tattooer friend told me about the "old days".
A heavily tattooed person, usually with a full body-suit, could sell their skin to a wealthy art collector for money now, with the promise that your skin would hang on their wall after you were dead.
Obviously, after shelling out the money now on the promise of your skin later, you literally had a price on your head (well, in this case, skin...) So if you did sell your skin, you had to be a real badass, knowing that everywhere you went, any time, any place, there was someone who had been sent to kill you so that the collector could enjoy his purchase.
Kind of sick, and I'm not sure it happens too much these days, but probably every once in awhile. I have met a few people who said they would like for their tattoos to hang in a museum some day.
Not me, however. My tattoos will be buried with me unless I get in some kind of horrible fire, or motorcycle accident between now and then!