Japanese Eighth Area Army /Dai-hachi hōmen gun/ was formed on November 16, 1942 under the Southern Expeditionary Army Group for the specific task of opposing landings by Allied forces in Japanese-occupied Solomon Islands and New Guinea. It had its headquarters at Rabaul, New Britain and saw considerable combat in the Solomon Islands campaign, Bougainville campaign and New Guinea campaign.
According to the decisive battle motto of the 8th Area Army the Nikkō badge was enacted with the slogan of "Ten kills per person, slashing the skin and cutting the bones/一人十殺、皮を斬らして骨を断".