Nakajima Aircraft Handa Plant

The Nakajima Aircraft Handa Plant (中島飛行機半田製作所) was a major aircraft production facility of the Nakajima Aircraft Company, established in Handa City, Aichi Prefecture on the Chita Peninsula. Construction began in the summer of 1942 (Showa 17), with main buildings completed by January 1943. The factory complex consisted of three principal facilities: the Main Factory (本工場) in the Kamihama-cho area, the Yamagata Factory (山方工場) in the Tōyō-chō (東洋町) area, and the Yoshino Factory (葭野工場) — the latter two being converted textile mills repurposed for wartime aircraft production.

At its peak the plant employed approximately 26,000–30,000 workers, including mobilized middle and high school students, unmarried women aged 14–25 under wartime labor conscription, and Korean forced laborers. The arrival of the factory transformed the local Otokawa village: the population surged from roughly 7,000 to over 30,000 as workers were recruited from across Japan. Massive infrastructure development accompanied the factory — farmland was leveled, coastal areas reclaimed, roads widened, railways extended, and a dedicated airfield constructed.

The Handa Plant's primary output comprised two naval aircraft types. The B6N Tenzan (天山, "Heavenly Mountain") carrier-based torpedo bomber entered production here with the first Handa-built unit completed on December 8, 1943. At peak capacity the plant produced 90 Tenzan per month, with an average monthly output of 49 aircraft and a total Handa production run of 977 aircraft. The C6N Saiun (彩雲, "Painted Cloud") carrier reconnaissance aircraft — famous as the fastest carrier-based aircraft in the Imperial Japanese Navy, capable of outrunning American F6F Hellcats — had its first Handa unit completed in June 1944, with a total of 427 produced at the plant.

The plant's dedicated airfield featured a single 924-meter runway oriented northwest to southeast. Because the southeastern end abutted a sea embankment, the runway was used for takeoff only — completed aircraft had to be transported elsewhere for flight testing and delivery. A circular turning pad at the northwest end of the runway remains identifiable in aerial photographs today.

On December 7, 1944, the devastating Tonankai Earthquake (昭和東南海地震, magnitude 7.9) struck the region, causing the Yamagata Factory buildings and worker dormitories to collapse. A total of 153 employees perished in the earthquake — part of 1,223 total regional casualties. The Japanese military government suppressed all information about the earthquake to prevent morale damage and to deny intelligence to the enemy.

In 1945, as strategic bombing intensified, plans were initiated to disperse production underground. In the Yokomatsu district of neighboring Agui Town (阿久比町), eight tunnel shafts were excavated into hillsides. Each tunnel entrance measured approximately 5 meters wide and 3 meters high, extending roughly 80 meters into the rock using pine timber supports in coal-mining fashion. Though intended as parts storage and eventual underground assembly facilities, the tunnels primarily served as air-raid shelters for factory workers and local residents.

The plant suffered two major air raids in July 1945. On July 15, 1945, about a dozen USAAF P-51 Mustang fighters from Iwo Jima, attacking in formations of three to six, conducted low-altitude strafing attacks that killed eight civilians and left machine-gun bullet holes in the brick walls of storage buildings. On July 24, 1945, a massive B-29 Superfortress bombing raid struck at 10:38 AM, lasting 18 minutes. Around 2,150 bombs were dropped, with 1,665 hitting the main factory complex directly. Eighty-one buildings sustained direct hits and 35 more suffered secondary damage. Because employees had been told to stay away from work that day, deaths inside the plant itself were few, but dormitories and housing were hit; estimates of the dead range from 134 (prefectural police history) to 261 (a local citizens' survey, which counted 120 Nakajima employees among them). Total war casualties in Handa City exceeded 430 people.

After Japan's surrender, the Nakajima Aircraft Company was dissolved. The Handa plant site was converted to civilian industrial use, becoming part of Yusoki Kogyo Co., Ltd. (a Fuji Heavy Industries / Subaru subsidiary). The Yamagata Factory site now houses Handa City Hall; Handa Municipal Hospital also stood there until it relocated in 2025. Parts of the former runway alignment and the circular turning pad are still discernible in the modern street grid and aerial photographs. The underground tunnels in Agui remain as war ruins, though most are sealed. A peace memorial monument erected in 1995 lists the names of all air-raid victims, including 48 Korean laborers who perished.