The History of Hitoyoshi Naval Air Base
Prior to World War II, the area around this museum was a sparsely inhabited plain tucked in the hills of southern Kyushu, covered in pine forests and fields of wildflowers, disturbed only by birdsong. It was said to be the site of a battle centuries earlier, but no traces remain. It was an isolated slice of rural Japan until everything changed in the autumn of 1943.
The war between Japan and the Allied forces had been raging for almost two years. Japan’s early advances in the Pacific had been halted in battles at Midway and the Solomon Islands the year before. Japanese forces were in slow retreat, with units evacuated from Guadalcanal, and the British beginning to retake territory in Burma. American submarines were taking an ever more deadly toll on Japanese shipping.
Most Japanese were unaware of the seriousness of these setbacks, but the country’s military leaders started making plans for Japan’s homeland defense. In November 1943, construction began here on an airfield to serve as a relay and supply base for other naval bases in southern Kyushu.
Military Operations Begin
Hitoyoshi Naval Air Base opened in February 1944 with a 1,500-meter-long runway and buildings for headquarters, training facilities, and barracks. For a year it fulfilled its mandate, including the housing and training of more than 6,000 teenage soldiers, some as young as 16. The advancing Allied forces still seemed far away, and photos in the exhibit show an enthusiastic group of trainees making mochi rice cakes and conducting military reviews.
By March 1945, however, the situation on the home front had deteriorated. The firebombing of Tokyo by U.S. aircraft on March 10 killed over 100,000 residents in a single night and left 1 million homeless. Meanwhile, outnumbered Japanese forces were furiously defending the southern island of Iwo Jima from a landing by U.S. Marines. The war came home to Hitoyoshi Base on March 18, when 14 American planes attacked the facility, damaging the airfield, destroying buildings, and killing 13, including 4 civilians.
Going Underground
By April, defense of the homeland had become the entire focus of Japan’s military strategy. Okinawa was slowly being overrun by Allied forces, and Hitoyoshi Base, like many places around Japan, was once again hit by U.S. bombers. The base was converted to a training site for kamikaze pilots flying the Type 93 trainers known as Akatombo (Red Dragonfly). Large underground tunnels were dug out of the volcanic rock for use as air raid shelters, barracks, and torpedo factories. In June, as conditions worsened, air training ceased and the remaining airmen, along with local civilians, underwent training in hand-to-hand combat in anticipation of a final battle on the Japanese mainland against invading forces.
That invasion never came, however. The atomic bombings of Hiroshima on August 6 and Nagasaki on August 9 were quickly followed by the Showa emperor’s broadcast capitulating to Allied demands on August 15. The war was over.
The Return to Peace
Many military documents from Hitoyoshi Base, as well as uniforms and other materials, were burned soon after the war’s end. According to the testimony of former servicemen stationed there, enlisted men were demobilized immediately, while others remained for several months for processing. Approximately 700 Occupation forces were stationed in the Hitoyoshi area as of November 1945. Over the years after the Occupation, some of the buildings were converted to other uses, ranging from schools to cattle sheds, while the underground tunnels were often used as storehouses by local residents.
Managing the Memories
In 2015, 70 years after the end of the war, a local historian found documents that shed light on the base’s role. They describe the base facilities, including the huge tunnel system and the runway (now the straight stretch of road leading to the museum). The town of Nishiki opened the Secret Base Museum in 2018, providing guidance to the tunnels and other remnants of the base, including a partially restored military gate 2 kilometers north of the museum and the ruins of a pine oil production workshop.
