21st Independent Mixed Brigade (Imperial Japanese Army)

Formed in January 1941 in Osaka, Japan, the brigade consisted of a single infantry regiment and support elements.

[6] Commencing in May 1942, the brigade undertook occupation duties in Hanoi following the Japanese invasion of French Indochina, as part of the Southern Army.

[7] This was followed by a move to Malaya and then Rabaul at the end of the year,[2] although the brigade's motor transport remained in Indochina.

[10] Consequently, the brigade's troops were scattered over several areas (the Mambare River, the Kumusi, Giruwa), before concentrating around Napapo, to the west of Gona.

[8] Around January 1943, the Japanese began evacuating Giruwa and elements of the brigade, totalling about 270 troops, withdrew to the Kumusi River.