The Royal Hawaiian Army, was established by the Japanese authorities occupying Hawaii after the victory in the North Pacific a month earlier. Roughly the size of a battalion, it was initially a purely ceremonial organization, though King Stanley Owana Laanui did insist that the Army receive functional weapons. Their arms mainly consisted of captured Springfields, and they were used to garrison the Iolani Palace. Much later, at King Stanley's insistence, they were allowed live ammunition for their weapons.

At first, many in both branches of the Japanese Armed Forces looked upon the army with suspicion and distaste, seeing the majority of them as cutthroats, thieves and opportunists, but as it became clear that the United States was going to invade Hawaii again in 1943, the Japanese were grateful for the extra help. If the need ever arose, General Yamashita planed to used them as cannon fodder, chewing up the Americans while preserving his own troops.

When U.S. forces returned in the summer of 1943, King Stanley threw the Royal Hawaiian Army into the defense of Schofield Barracks. Its performance in the battle proved to be mixed. Many units fought more tenaciously than the Japanese did, often to the death, driven by a furious hatred of the haoles. Others, realizing their cause was doomed, surrendered after token resistance. This led to mixed feelings for the soldiers on both sides.

After this defeat, what little remained of the Army was withdrawn to bolster the defense of Iolani Palace. Alongside what remained of the Japanese Army, they fought side by side to the death.