KOKU (100.3 FM) – branded as Hit Radio 100 – is a commercial contemporary hit radio (CHR) radio station licensed to Hagåtña, Guam. It is owned and operated by Moy Communications Inc.

The is a Japanese unit of volume, equal to ten cubic shaku. In this definition, 3.5937 koku equal one cubic metre, i.e. 1 koku is approximately 278.3 litres. The koku was originally defined as a quantity of rice, historically defined as enough rice to feed one person for one year (one masu is enough rice to feed a person for one day). A koku of rice weighs about 150 kilograms (23.6 stone or 330 pounds).

Kokū (虚空) or Koku is a honkyoku, a solo "original piece" of Japanese Buddhist origin for the shakuhachi, a bamboo flute. The title "Kokū" is often translated as "empty sky".