By prefecture
Where we have checked so far. Coverage grows region by region.
Oita
43 onsen · 32 welcome tattoos · 5 open to day visitors
Kanagawa
28 onsen · 17 welcome tattoos · 11 open to day visitors
Hokkaido
23 onsen · 3 welcome tattoos · 17 open to day visitors
Gunma
22 onsen · 7 welcome tattoos · 5 open to day visitors
Hyogo
16 onsen · 6 welcome tattoos · 2 open to day visitors
Wakayama
16 onsen · 1 welcome tattoos · 3 open to day visitors
Tokyo
15 onsen · 7 welcome tattoos · 2 open to day visitors
Kyoto
14 onsen · 2 welcome tattoos · 7 open to day visitors
Osaka
14 onsen · 3 welcome tattoos · 2 open to day visitors
Hiroshima
13 onsen · 2 welcome tattoos · 5 open to day visitors
Ibaraki
13 onsen · 1 welcome tattoos · 2 open to day visitors
Shimane
13 onsen · 0 welcome tattoos · 4 open to day visitors
Toyama
13 onsen · 1 welcome tattoos · 8 open to day visitors
Kumamoto
12 onsen · 2 welcome tattoos · 3 open to day visitors
Nara
12 onsen · 0 welcome tattoos · 2 open to day visitors
Tochigi
12 onsen · 0 welcome tattoos · 2 open to day visitors
Fukuoka
11 onsen · 0 welcome tattoos · 6 open to day visitors
Nagano
11 onsen · 0 welcome tattoos · 1 open to day visitors
Gifu
11 onsen · 0 welcome tattoos · 4 open to day visitors
Nagasaki
11 onsen · 1 welcome tattoos · 3 open to day visitors
Okinawa
11 onsen · 3 welcome tattoos · 8 open to day visitors
Saitama
11 onsen · 1 welcome tattoos · 1 open to day visitors
Shizuoka
11 onsen · 3 welcome tattoos · 2 open to day visitors
Aichi
10 onsen · 3 welcome tattoos · 5 open to day visitors
Chiba
10 onsen · 4 welcome tattoos · 6 open to day visitors
Ishikawa
10 onsen · 0 welcome tattoos · 1 open to day visitors
Mie
10 onsen · 0 welcome tattoos · 7 open to day visitors
Shiga
10 onsen · 3 welcome tattoos · 3 open to day visitors
Tottori
10 onsen · 3 welcome tattoos · 2 open to day visitors
Yamanashi
9 onsen · 2 welcome tattoos · 1 open to day visitors
Niigata
8 onsen · 0 welcome tattoos · 0 open to day visitors
Akita
8 onsen · 0 welcome tattoos · 7 open to day visitors
Tokushima
5 onsen · 0 welcome tattoos · 4 open to day visitors
Aomori
4 onsen · 1 welcome tattoos · 4 open to day visitors
Yamagata
4 onsen · 0 welcome tattoos · 0 open to day visitors
Ehime
4 onsen · 3 welcome tattoos · 1 open to day visitors
Miyagi
3 onsen · 0 welcome tattoos · 1 open to day visitors
Fukushima
3 onsen · 1 welcome tattoos · 1 open to day visitors
Fukui
2 onsen · 0 welcome tattoos · 0 open to day visitors
Iwate
2 onsen · 0 welcome tattoos · 2 open to day visitors
Kagoshima
1 onsen · 0 welcome tattoos · 0 open to day visitors