Walter Oka was born in May 1928 in a hospital in Ewa, but spent his young childhood in the town of Waianae, Oahu, Hawaii, where his family, that included 12 children, occupied a one room house. His father operated a truck farm until the water supply was diverted, after which he moved to his family to Aiea, where he worked on a sugar plantation. They took up residence in what had been the plantation hospital nurses' quarters, vacated when a new facility was built, which had a porch facing Pearl Harbor. All of Oka's extended family lived in Japan, and it was Oka's impression that his father meant to make a fortune in Hawaii and return to Hiroshima as a prosperous land owner and farmer. But he never went back to Japan. Oka said he was too young to know that he was living through the Great Depression, and reckons that because his parents had a productive vegetable garden and chicken coop, and he and his brother could fish in Pearl Harbor, they were never hungry. Although she was not highly educated, his mother was the "financier" of the family, and managed money very well. Oka went to grade school in Aiea, then transferred to Waipahu for high school, graduating in June 1946. The ongoing political difficulties of the war in Europe and the Japanese aggression in the East were never discussed among his family members.

As a kid, Walter Oka used to hang around on the pier, selling newspapers and sundries to the sailors. He collected match covers of all the ships, and knew their mooring locations. In 1941, after the ships had been out on maneuvers, they would parade into the harbor on Friday evenings and go out again on Monday mornings. On Sunday mornings, the air forces would fly in formation and practice dive bombing. Oka would watch all of this weekend activity with interest. When, on the morning of 7 December 1941, he heard a loud explosion and the roar of airplanes and machine gun fire, he and some of his siblings went out to the porch to see what was happening. He saw planes diving and dropping bombs, and on the southwest part of the island he saw the USS Utah (BB-31) capsizing. Looking toward Battleship Row, he saw the USS Oklahoma (BB-37) foundering, and the USS Arizona (BB-39), with a horrendous sound, explode. His body was moved backwards an inch or two from the concussion. Oka remembers that after about 30 minutes of continual attack on the ships, things became quiet, and he began to discern the explosions of ammunition, tanks and oil supplies. In another 30 minutes, he witnessed another aerial attack, and for the first time saw antiaircraft guns and machine gun fire knocking a few of the planes from the sky. One plane, he remembers, blew up in the air, and several started to burn and fell into the harbor. At one point, the roof of his home was riddled with machine gun fire, but the children, insensible of what had happened, kept on watching the scene of destruction. Once again, the planes left, and the sounds returned to the minor explosions happening around the area. Little boats began gathering in the harbor in what Oka supposes were rescue operations. Oka was 13 and a half years old, and he recalls thinking to himself that the Army was really mad at the Navy and they are dropping real bombs and killing their own men. He looked up to see a plane flying over his house and realized the aircraft was Japanese. He learned later that there were others who also thought it was a mock attack. It turned out that Oka had a "bird's eye view of the beginning of the war." In his naiveté, he looked upon it as "some spectacular show."

Once the Japanese attack on Pearl Harbor died down, Walter Oka and his siblings continued to watch the goings on for a couple of hours. A temporary graveyard was established near their home, and they saw trucks carrying blood-stained wooden coffins passing by. There was a radio announcement that students in the University of Hawaii ROTC [Annotator's Note: Reserve Officer Training Corps] should report to duty, and Oka's brother, a freshman there, answered the call. Eight weeks later, he was stripped of his weapons because he was a "Jap," [Annotator's Note: period derogatory term for Japanese] and according to Oka, he was really mad. Oka notes that the same thing happened to about 1,400 Nisei that were drafted in 1940 and 1941. Oka explained that in Japanese culture, Nisei is a numerical reference to the second generation. They were put in the Schofield Barracks where they stayed until May 1942 when they were shipped to Camp McCoy in Wisconsin for further training under the watchful eyes of the military. But the soldiers excelled in everything they were asked to do and in 1943, the 442nd all Nisei Regimental Combat Team [Annotator's Note: 442nd Regimental Combat Team] of about 3,600 men was formed from that group. For Oka, who was still too young to serve, there was no school for a while, and he remembers that when it resumed he practiced taking cover in bomb shelters, and using a gas mask. Food and supplies were rationed, there was a curfew from twilight to dawn, and blackout shades were built for the windows of their house. Pearl Harbor was off limits, so Oka could no longer go fishing or crabbing there; he has never gone back to the pier.

Asked about discrimination in Hawaii, Walter Oka observed that the Filipinos that lived in the area held animosity for the Japanese because of the invasion of their islands. He got into a fight with a couple of Filipino kids and lost some of his teeth. But, in general, Oka said he didn't personally experience some of the animosity that some of the older guys may have had. At that time, the Japanese [Annotator's Note: Japanese-American] men were reclassified as 4-C, meaning they were an enemy alien and his older brothers could not volunteer. Even so, Japanese-Americans could volunteer to be in the Military Intelligence Service if they had proficiency in the language. His family didn't fret about the situation, and Oka even worked in the PX [Annotator's Note: Post Exchange] during his summer vacations. Oka mentioned that his ID photograph for the job was taken against a black backdrop to demonstrate that he was an enemy alien, and he was restricted from certain places. After the valorous action of the Japanese-American troops in battle, however, Oka said the second generation Japanese were classified 1-A [Annotator's Note: Selective Service classification indicating that an individual is fit for military service] again, and were drafted as replacements for the all-Japanese units. Oka also mentioned that there were Japanese-Americans citizens called Kibeis who went to Japan, attended school at some level, and came back to the United States before Pearl Harbor was attacked who proved very important in the service in the Pacific because they could read Japanese cursive.

Under the influence of his sister who was a nurse, Walter Oka was thinking of studying to become a laboratory technician after he graduated from high school. He had been following the war, and particularly the 442nd [Annotator's Note: 442nd Regimental Combat Team]. Once they could do so, all seven of Oka's brothers volunteered, and four of them served during the war. Oka had no real interest in getting into combat, but wanted to join the Army to take advantage of the G.I. Bill. Oka joined the Army in August 1946, hoping to be in the medical corps, and volunteered to go to Japan for three years. He took basic training in Hawaii and went to Japan, ending up in the replacement depot in Yokohama. At the time the rate of discharge of interpreters was very high, and his plans for medical training were redirected. In retrospect, he has no regrets; he got to see a lot of Japan as an interpreter. He was sent to Tokyo to learn military Japanese, and Oka was delighted with the first class dining and living conditions there. From there he went to Kyoto for deployment, then to Hario Island. He lived in a Quonset hut, and worked interrogating civilians and military personnel coming back from Java, Malaysia, Indochina and the Philippines prison camps. On the whole, Oka said, the prisoners of war were treated fairly well. Oka was on the island for about four months, after which he was transferred to Miyazu where he had better living conditions. In Miyazu he was interrogating prisoners coming back from Russia.

Walter Oka said the conditions under which the POWs [Annotator's Note: prisoners of war] were transported were sparse, but clean. Surprisingly, they were in good physical condition. Some of them had held important posts in Russia, supervising the re-establishment in that country of industrial facilities that had been confiscated from the Japanese as spoils of war. Some were GIs who had been captured in Manchuria and had been working in forestry. While he was stationed in Japan, Oka found that the natives were surprised that he was of Japanese descent, but his mannerisms separated him from them. The Japanese-Americans are straightforward, according to Oka. The interpreters got along with the population they encountered, and claims to have been a non-political person at that time. When the Red Cross notified Oka that his mother was near death, he was allowed to return to Hawaii. He found his mother recovered, but because he only had seven more months to serve, the Army would not send him back to Japan. He spent the rest of his tour of duty at Fort Shafter in Honolulu, Hawaii, with little to do. He ended up in a motor pool, and was discharged in July 1949.

His service as a Nisei [Annotator's Note: first generation Japanese-American] soldier was important to Walter Oka because he was treated like an American and had the opportunity to prove his loyalty. It was the attitude of the Nisei to "Go For Broke," and they accomplished the highest honors in service, in spite of heavy losses. Oka said his most memorable experience of the war was watching the Japanese attack on Pearl Harbor. He eventually used the G.I. Bill to get a BS in zoology and a masters' degree in immunohematology, which set him up for life. The war exposed him to things he would not have known otherwise. He enjoyed the camaraderie of military life. He is considered a World War 2 veteran, and he feels bad about getting credit when he never was in combat. President Truman [Annotator's Note: President Harry S. Truman] declared that anyone who volunteered before 31 December 1946 would be recognized as a World War 2 veteran, and he fit the criteria. He thinks of The National WWII Museum as one would a library for the history of the war. He doesn't feel that the subject is adequately covered in schools, particularly as it pertains to the Nisei soldiers, and fears that history will repeat itself if we don't learn from the lessons of the war.