Kikaijima Shin'yō Storage Tunnel
Kikai Town, Kagoshima Prefecture
The 40th Shin'yō Special Attack Squadron, with one-man motorboats loaded with
explosives to make suicide attacks against American ships, had its base in 1945
next to Sou Harbor in the northeast part of Kikaijima, an island 380 kilometers
south of the southern tip of Kyushu.
A portion of one of the tunnels used to hide the shin'yō motorboats has been
preserved. The back part of the tunnel has now been filled in with rocks and
concrete. The sign to the left of the tunnel gives the following information:
Shin'yō Storage Tunnel
This is the site of a storage tunnel for small wooden shin'yō (also called
maru yon) special attack motorboats, which carried 250 kilograms of
explosives. Near the end of the Pacific War, the Navy planned to use them in
taiatari (crash) attacks against American ships trying to land on
In this area several tunnels located about 50 meters toward the interior
were used to store 50 boats. They were also deployed to Onotsu .
Along with the Navy Construction Corps (Miyamoto Unit), third-year
students from Oshima Junior High School constructed the tunnels. With a
system of two shifts per 24 hours, they were completed in a short period of
On February 11, 1945, soon after construction of the tunnels, the 187 men
of the 40th Shin'yō Squadron under the command of Lieutenant Sueyoshi Andō
were stationed here. The Andō Unit set up headquarters in the mountains at Shiomichi. They waited for orders to make a sortie, but the American
task force never approached near. The war ended finally without one boat
ever making a sortie.
About 6,000 shin'yō boats were built by the war's end. The only one that
remains is at the War Memorial Museum in Sydney, Australia .
According to the history of the 40th Shin'yō Special Attack Squadron written
by former squadron commander Sueyoshi Kojima , the squadron
had 192 total members with 8 officers (including medical officer), 50 shin'yō
boat pilots, 21 headquarters personnel, 35 maintenance workers, and 78 other
The shin'yō boat pilots trained in Nagasaki Prefecture at the Kawatana Torpedo Boat Training
School. The 40th Shin'yō Special Attack Squadron
officially formed on January 25, 1945. The squadron's members originally used
the elementary school and civilian houses in Sou Village to live, but these were burned in
heavy air attacks. They then moved to stay at the foot of the mountains in crude
shelters built with gajumaru (Malayan banyan) wood.
The squadron commander's history states that during the war one shin'yō pilot
and two base workers died and nine other squadron members were wounded. He does not mention how these
casualties occurred, but they most likely were during air attacks on Sou
The historical information about the 40th Shin'yō Special
Attack Squadron is from pages 84-5 (written by Sueyoshi Kojima, former 40th
Special Attack Squadron commander) of the following book:
Shin'yō Association (Shin'yōkai), ed. 1990. Ningen heiki:
Shin'yō tokubetsu kōgekitai (Human weapon: Shin'yō Special
Attack Corps). Shirō Arai, general editor. Volume 2 of 2. Tōkyō: Kokushokankōkai.
1. The 111th Shin'yō Special Attack Squadron, which
had 2-man Model 5 shin'yō boats, was stationed at Onotsu, which is located on the
western side of the northern tip of the island of Kikaijima.
2. The Australian War Memorial is located in
Canberra, not Sydney. Also, it could not be confirmed that the museum at the
Australian War Memorial has an
actual shin'yō motorboat from WWII.
3. Kojima is his married family name. Andō was his
family name during the war.