Did the navy dig a bunker in Nagano, where there is no sea?

What is your intention?

August 17, 16:32

Traces of underground bunkers that still remain in Nagano City.

One of them is believed to have been dug by the Navy.

As a matter of fact, what was the navy trying to do in Nagano, far from the sea?

In order to investigate, the reporter visited the site many times and interviewed the people involved.

In the summer of 1977 from the end of the war, we approached the secret story of the Pacific War.

(Nagano Broadcasting Station Reporter Shinya Hashimoto)

Underground bunker under construction in Nagano City

Speaking of war ruins of the Pacific War that remain in Nagano, it is probably "Matsushiro Imperial General Headquarters".

Towards the end of the war, an underground bunker was being constructed in preparation for the decisive battle on the mainland. It is said that the plan was to relocate the headquarters of the military and government, as well as the living quarters of the emperor, from Tokyo.

In addition to a huge underground bunker that stretches more than 10 kilometers, there is also a nearby building that was supposed to be the temporary Imperial Palace.

There is actually an underground bunker in the Amori area of ​​Nagano City, about 10 kilometers across the Nagano Basin from the Matsushiro Imperial Headquarters.

It is located on a hill where you can see the Matsushiro direction.

This underground bunker is 2.5 meters high, over 3 meters wide, and it is said that the war ended when it was dug up to about 100 meters.

After the war, it was known in some parts of the area, as evidenced by stories that children used to play with it, but its purpose and other details remain unknown.

The trigger is the village chief's diary

What is the underground bunker that remains in this Amori area?

There is a group investigating this mystery.

It is a group of local residents and former high school teachers who investigated the Matsushiro Imperial General Headquarters.

It was the discovery of a diary from 10 years ago that triggered the full-scale investigation.

Gohachiro Tsukada.

It is the diary of a person who was the mayor of the village at the time.

It was found in the storehouse of Tsukada's home, and the diary describes the movement of the village from May to November 1945.

And from the diary, it seems that it was the navy that was involved in this bunker.

Secretary General Tsuchiya

: “It’s rare to find objective writing from a public position as a village chief. It specifically describes what a navy officer was doing in Amori. I thought it was a document of

What happened in Amori just before the end of the war?

Quoted from the diary of Mayor Tsukada.

・On June 28, 1945,

officers from the Naval Engineering Department and the Imperial General Headquarters came.

There was a request for a cave-proof hole and lodgings for emergencies.

・On July 26, 1945,

Captain Sukeichi Sumitani of the Yokosuka Naval Arsenal Military Construction Department Sonoda Corps came.

He had an application to rent a lodging house.

・On August 5, 1945,

a unit requested to purchase 10,000 kan (37.5 tons) of firewood and charcoal.

It is written that the navy was active in Amori at the end of the war, including the contents of the request for various conveniences in the village.

Episodes showing involvement with the navy

In order to ascertain whether anyone still knew the contents of this description, the association repeatedly conducted surveys in the surrounding area.

Then, Sachiko Oya, who was 13 years old at the end of the war, clearly remembered that soldiers used to sleep in a nursery school about 400 meters away from the bunker.

Mr. Oya:

“I remember that there was a kitchen and a place where we ate rice around here.

Furthermore, Mr. Oya testified that the color of the clothes worn by the soldiers was "like brown."

According to the association's secretary-general, Tsuchiya, the uniforms suggest that the unit here was a naval land force.

It can be said that it is an episode that understands the relationship between the Navy and Amori.

A clue to the purpose of the bunker

Items related to the navy were discovered in the area, and the Association has opened a new museum to introduce these items.

At the museum, there is a nameplate written by the navy that says ``Navy Sonoda Unit'' and a plate with an anchor mark on it.

There are other clues to the purpose of this bunker.

There is a record that the 300th Construction Corps, which actually dug the underground bunker, dispatched an investigator in June 1945 to conduct a preliminary survey on the construction of the Nagano facility of the Tokyo Communication Corps.

After the war, an officer of this construction unit told the National Institute for Defense Studies, "Since there is no room for the navy to enter the underground bunker of the army, it was decided to build a new one that could accommodate 1,000 naval general staff. (From "Looking Back on the History of Nagano Prefecture").

Professor Akira Yamada of Meiji University's Faculty of Letters, who studies modern military history, also pays attention to the village mayor's diary and underground bunkers as clues to the truth of the all-out resistance.

Lieutenant Colonel Miki Sonoda, the commander of the ``Naval Sonoda Unit'', who is also mentioned in the diary and the nameplate, was a person who advanced the communication field, and Professor Yamada believes that the communication unit was visiting.

He points out the following while saying that it is impossible to say for sure because there are no official records left.

Professor Yamada

: "First of all, we will place the function of communicating with the Combined Fleet Headquarters in Hiyoshi, Yokohama City in Amori, and then move the functions of the Ministry of the Navy and the Naval General Staff in Tokyo to Nagano for the mainland battle. It is not generally known that the navy dug trenches, but it is true that they did. In Nagano, the army-led Matsushiro Imperial General Headquarters is famous, but from these diaries and underground bunkers, we can see that there were forces within the navy who were also working to put up a thorough resistance.”

Are you ready for the mainland decisive battle?

A large-scale plan was being worked out to move the center of the nation not only to Matsushiro and Amori, but also to the entire area around Nagano City and to fight with all their might.

The conference makes the following assumptions.

Located in the mountains about 5 kilometers from Amori in a straight line, there is a railway tunnel that was already closed at the end of the war.

A local student who worked here at the end of the war wrote in his anthology after the war that ``the tunnel was loaded with anti-aircraft gun ammunition until it was full''.

Also, at the end of the war, kamikaze units were relocated from Kyushu to Nagano, so it is believed that Nagano was not just a place of refuge, but that many war facilities were built in preparation for a decisive battle on the mainland.

At the end of the war, a big man from the army was visiting Nagano.

Korechika Anami, Minister of War.

He was inspecting this place a short distance from Amori.

Morihito Hirabayashi, commander of the Nagano District who accompanied the inspection, wrote in his postwar memoirs, ``After the emperor moved to Matsushiro, the problem was what to do with the Empress Dowager (the mother of the emperor). If so, we will be fine no matter what kind of bombing we receive. The hot springs are also nearby, so it's convenient," said Minister Anan.

In addition to Matsushiro, where the emperor moved to, Nagano was positioned as an important place of refuge for the imperial family.

Why is the center of the country in Nagano?

The tunnel is now infested with bats and is crumbling in parts.

Why did they decide to move the center of the nation to Nagano, deep in the mountains?

And why did you go to such lengths to continue the war?

The Association for Handing Down Showa Amori says that they would like to conduct a survey to elucidate its intentions.

Co-Representative Okamura

: I have a sense of crisis that the war will be forgotten as time goes by. Investigating it will also help prevent memories of the war from fading.”

Interview postscript

``The war is over for the navy to dig a hole in a mountain like

this. ''

What were the soldiers thinking when they dug the mountains of Shinshu?

Many of the victims died, and their bereaved families say they have not heard any details about the Amori bunker.

Seventy-seven years after the end of the war, I am overwhelmed by the enthusiasm of the residents to find out more about their local history.

I will continue to pursue the mystery of this underground bunker.

Nagano Broadcasting Station Reporter

Shinya Hashimoto

Joined in 2014

After working at Tottori and Maebashi stations, in charge of Nagano city administration at Nagano station

Continuous coverage of underground bunkers at the end of the war