Within two months of the attack on Pearl Harbor, all American citizens of Japanese ancestry had been discharged from the Hawaiian Territorial and National Guard. The 100th Infantry Battalion, composed entirely of volunteers, came into existence because Americans of Japanese ancestry living in Hawaii demanded the chance to defend the United States. Members called it the "one puka puka", Hawaiian for one hundred.

After fighting their way up the Italian peninsula, the 100th would eventually be joined by the 442nd Regimental Combat Team, a second segregated Nisei military unit. The 100th/442nd saw action in Italy, Belgium, southern France, and Germany. At war's end, 680 members of the unit had been killed in action, 67 were missing, and 3,600 Purple Hearts including 500 Oak Leaf Clusters had been awarded for wounds suffered in combat. Their motto was, "Go for Broke."

On October 27, 1944, after 10 days of heavy fighting in southern France, the exhausted men of the 100th/442nd were awakened by orders to rescue the men of the 1st Battalion of the 141st Regiment, 36th Division, who had been surrounded by the Germans near Biffontaine. In the drizzle and darkness, the 100th/442nd moved out into an action that would be three days of hell on earth.

"In the battle for the lost battalion, every inch, every knoll and hill we took, we had to fight like hell. The Germans tried to stop us in every way... I know a lot of people say that it was a foolish campaign. But to me it was the pride of the Army... You can't allow a battalion to get surrounded and not do anything about it. You can't allow them to get wiped out." —Rudy Tokiwa, Go For Broke

"Whenever you have been near enough to see these boys die for their country, then is the time to voice your opinion... When you have seen these boys blown to bits, going through shellfire that others refused to go through, sleep, when they could, in foxholes half full of water, and other horrors not to be mentioned — then is the time to voice opinion. Not before..."
—Letter from the "Red Bull" Division