This sumo wrestler signing autographs has a fast and effective method. He impregnates the palm of his hand in ink and stamps his handprint. His assistant places sheets of paper and he slaps them at high speed. The sumo wrestler is so fast that sometimes the helper does not have time to place the paper.
Maybe he hasn’t noticed that giving away his fingerprints is creating a security problem. If he has a fingerprint lock device, anyone can access it, as the great MythBusters have already shown (thanks for the comment, Nacho).
The scene has reminded me of the huge slaps Bud Spencer gave in his films. Those punches that sounded like hitting a wooden plank with a wall.
If you like the way Bud Spencer stamps autographs on the faces of his enemies, this Youtube video can be interesting: Bud Spencer slap compilation.
Touching the palm of this sumo wrestler’s hand must be like touching a grizzly bear paw. It must look like it’s made of hard leather.
I think with that strength and that hand this Japanese would make a good Basque ball player. His hand must be as calloused as those who practice this sport.