In 1940, Hawaii was still a territory of the United States — statehood would not be achieved until 1959. Thriving fields of sugar cane dotted the landscape of most of the Hawaiian Islands. They had been made productive and profitable with immigrant labor, first from China and then from Portugal.
The first large-scale group of immigrants from Japan arrived in Hawaii in 1885; they were known as kanyaku imin, or contract immigrants. Tens of thousands more would follow, most of them from famine-stricken villages in southern Japan. By 1902, some 30,000 Japanese had crossed the Pacific Ocean to labor in the sugar cane fields of Hawaii. By 1940, the Japanese population had grown to nearly 160,000.
The first generation Japanese immigrants, the Issei, gave birth to the Nisei, the second generation, from which would come the majority of the 100th Infantry Battalion soldiers. This new generation of Americans of Japanese ancestry (AJA) was raised in a multicultural environment where such traditional Japanese values as loyalty and duty to family, community and country were melded with the American principles of freedom and democracy that these young AJAs learned in their public school classrooms. Although raised in close-knit Japanese communities, the Nisei could not help but be influenced by the native Hawaiian culture of the islands as well as the culture and customs of the many immigrant groups that had settled in Hawaii.
While many Issei settled into a life on the plantations that had been made better due to the efforts of organized labor, others yearned for a life beyond the sugar cane fields and opened small businesses or became tradesmen.
Like other ethnic groups who immigrated to the United States, the Issei understood that education was key to their children having a better life, so they sacrificed greatly to send them to college. However, even with a college degree under their belts, racial discrimination barred most Nisei from positions in large Caucasian-owned companies; many of them turned to the teaching profession.
While many Nisei had graduated from high school and some had gone on to higher education at the University of Hawaii or to colleges on the Mainland, that was not the case for all, particularly those who served in the original 100th Infantry Battalion. For many of them, graduation from high school — even the eighth grade — had to suffice so they could help their parents support their large families. These men in the 100th were generally five to seven years older than their counterparts in the other Nisei military units when they departed for training on the Mainland. Many were working, and some were already married and had started families.