This is a chart showing those (larger) countries with the highest % of adults who have at least one tattoo
https://www.statista.com/statistics/...ted-countries/

1 Italy 48%
2 Sweden 47%
3 United States 46%
4 Australia 43%
5 Argentina 43%
6 Spain 42%
7 Denmark 41%
8 United Kingdom 40%
9 Brazil 37%
10 France 36%
11 Germany 36%
12 Greece 35%
13 South Africa 33%
14 Russia 33%
15 Canada 33%
14 Mexico 32%
15 Turkey 30%


If you whittled out the older demographic and narrowed the focus to 18 to 40 year olds, those percentages are going to be higher still.
From that younger subset, focus in further on people who actively aim to go to Japan and it becomes clear that the majority of visitors from that country are inked.

Kinosaki’s innkeeper association (or equivalent) have been extremely astute.