it's traditional tattooing called tebori, there were no machines in past so they use needlestick tied to a bamboo stick and rapid hand movement to press the ink into the skin. it takes a very long time and multiple sessions. the sound effect is a little strange? it makes sha-sha sound and not slice
and it's very painful too, if we compare it to modern style.
Oh so it's not really slicing? I was imagining it the whole time and can't help but wince when I see the word 'slice'
Oh god. Me too. I literally thought SLICE means cutting through the skin in vertical or what shape to let the ink seep.
I think there are certain cultures or traditions that would cut the skin to allow ink in or rub ink in, but I'm not really sure of where and I don't think Japan or east Asia generally had that tradition...
Different types of scarification has been common in a lot of ethnic groups in Africa though
What kind of method was that tattooing? I'm only familiar with the old style that uses some kind of flower/plant?