| Code | Name | Region |
|---|---|---|
| JPKKU | Kuji, Kagoshima | 46 |
| JPKRR | Kujiragaura | 42 |
| JPKGB | Kuka | 35 |
| JPKKY | Kuki | 11 |
| JPKMG | Kumagaya | 11 |
| JPKGE | Kumage | 44 |
| JPKGO | Kumago | 38 |
| JPKMJ | Kumamoto | 43 |
| JPKUU | Kumanoe | 45 |
| JPUEO | Kumejima | 47 |
| JPKMS | Kumeshima | 47 |
| JPKMH | Kumihama | 26 |
| JPKNH | Kunehama | 42 |
| JPKNG | Kuniga | 32 |
| JPKNS | Kunisaki | 44 |
| JPKCI | Kunitachi | 13 |
| JPKHS | Kurahashi | 34 |
| JPKRC | Kuramai | 23 |
| JPKRN | Kuranotani | 32 |
| JPJKT | Kotoura | 33 |
| JPKTO | Kottoi | 35 |
| JPKOR | Koura, Kagawa | 37 |
| JPKJU | Koura, Kagoshima | 46 |
| JPKKR | Kouri | 47 |
| JPKWX | Kowa | 23 |
| JPKOY | Koyoh/etajima | 34 |
| JPKYO | Koyoh/kawajiri | 34 |
| JPKOB | Koza | 30 |
| JPKZJ | Kozai | 37 |
| JPKZE | Kozera | 42 |
| JPKZK | Kozukushi | 39 |
| JPKOZ | Kozuna | 42 |
| JPKBU | Kubuki | 42 |
| JPKBR | Kubura | 47 |
| JPKCF | Kuchinofukuura | 46 |
| JPKUC | Kuchinotsu | 42 |
| JPKJD | Kudadon | 46 |
| JPKUD | Kudamatsu | 35 |
| JPKUG | Kugui | 33 |
| JPKKE | Komukae | 42 |
| JPKNI | Konagai | 42 |
| JPKOF | Konan | 7 |
| JPKNC | Konan, Shiga | 25 |
| JPKNB | Konbukariishi | 1 |
| JPKNY | Koniya | 46 |
| JPZAC | Konohana-ku, Osaka | 27 |
| JPKON | Konoshima | 33 |
| JPNOS | Konosu | 11 |
| JPKNO | Konoura | 5 |
| JPKIY | Koriyama | 7 |