| Régions | Ligues préfectorales |
| | |
| Hokkaïdo | Hokkaïdo Rugby Football Union |
| | |
| Tohoku | Aomori Rugby Football Union |
| Tohoku | Iwate Rugby Football Union |
| Tohoku | Akita Rugby Football Union |
| Tohoku | Yamagata Rugby Football Union |
| Tohoku | Miyagi Rugby Football Union |
| Tohoku | Fukushima Rugby Football Union |
| | |
| Kanto | Ibaraki Rugby Football Union |
| Kanto | Tochigi Rugby Football Union |
| Kanto | Gunma Rugby Football Union |
| Kanto | Saitama Rugby Football Union |
| Kanto | Chiba Rugby Football Union |
| Kanto | Tokyo Rugby Football Union |
| Kanto | Kanagawa Rugby Football Union |
| | |
| Chubu | Niigata Rugby Football Union |
| Chubu | Toyama Rugby Football Union |
| Chubu | Ishikawa Rugby Football Union |
| Chubu | Fukui Rugby Football Union |
| Chubu | Nagano Rugby Football Union |
| Chubu | Yamanashi Rugby Football Union |
| Chubu | Gifu Rugby Football Union |
| Chubu | Shizuoka Rugby Football Union |
| Chubu | Aichi Rugby Football Union |
| | |
| Kansaï | Mie Rugby Football Union |
| Kansaï | Shiga Rugby Football Union |
| Kansaï | Kyoto Rugby Football Union |
| Kansaï | Osaka Rugby Football Union |
| Kansaï | Hyogo Rugby Football Union |
| Kansaï | Nara Rugby Football Union |
| Kansaï | Wakayama Rugby Football Union |
| | |
| Chugoku | Tottori Rugby Football Union |
| Chugoku | Shimane Rugby Football Union |
| Chugoku | Okayama Rugby Football Union |
| Chugoku | Ricoh Black Rams |
| Chugoku | Yamaguchi Rugby Football Union |
| | |
| Shikoku | Tokushima Rugby Football Union |
| Shikoku | Kagawa Rugby Football Union |
| Shikoku | Ehime Rugby Football Union |
| Shikoku | Kochi Rugby Football Union |
| | |
| Kyushu | Fukuoka Rugby Football Union |
| Kyushu | Saga Rugby Football Union |
| Kyushu | Nagasaki Rugby Football Union |
| Kyushu | Kumamoto Rugby Football Union |
| Kyushu | Oita Rugby Football Union |
| Kyushu | Miyazaki Rugby Football Union |
| Kyushu | Kagoshima Rugby Football Union |
| Kyushu | Okinawa Rugby Football Union |
