Issue:
March 2025
The 2011 discovery of radium in a Tokyo suburb can be traced back to a rightwing fixer who influenced Japan’s postwar politics

Luminous radium paint continuously emits a phantasmal dim green light throughout the night. And mysterious bottles of radium material, found in Tokyo after the disastrous Fukushima Daiichi nuclear meltdown 14 years ago, turned out to shed light on a historical nexus involving a Canadian mine, the Japanese Imperial Navy and a notorious fixer of underground criminal syndicates following World War II.
On October 13, 2011, seven months after the Great East Japan Earthquake, high levels of radiation were recorded on the street in Tsurumaki, a residential neighborhood in Tokyo's Setagaya Ward. Tsurumaki is quiet area of homes, primary schools, kindergartens and a public library. The hotspot was detected at a height of about one meter above ground, after Setagaya residents who had been monitoring radiation levels alerted the authorities. Technicians employed by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) recorded radiation of 3.35 microsieverts per hour, actually higher than some areas in the evacuation zone near the Fukushima reactor. They tracked the source to a nearby empty house, where beneath the floorboards they discovered a cardboard box in which several glass bottles were stored. The bottles turned out to contain Radium-226, a highly radioactive material.
At the time, people were still reeling from the meltdown at Tokyo Electric Power’s Fukushima Daiichi nuclear power plant, which had been badly damaged by a huge tsunami. The discovery caused a stir and the empty house attracted lots of TV crews. But after MEXT concluded that the radiation was unrelated to the Fukushima accident, the media promptly lost interest, and the mysterious bottles of Radium-226 soon faded from the public's attention.
What was source of the radium at the empty house in Setagaya? A clue to the unanswered question was the company name, Nippon Yako, that appeared on the labels of some of the bottles. At the end of World War II 80 years ago, one person had radium material from Nippon Yako in his possession. His name was Yoshio Kodama, widely known as an ultranationalist, former Class-A war criminal and a fixer for Japan’s rightist groups and underground criminal syndicates.
While it may be difficult to imagine today, it can be said that in the context of postwar Japan, Yoshio Kodama (1911-1984) led a rather bizarre existence. In his youth, he was no more than an ultranationalist thug. His name first popped up during the war, when he organized the Kodama Agency in Shanghai at the request of the Japanese Imperial Navy. His ostensible function was procurement of materials for the Japanese war effort, but he was essentially looting assets from Chinese.
Soon after the war’s end, the Supreme Commander for the Allied Powers labeled Kodama a Class A war criminal and ordered his arrest. He was incarcerated in Tokyo's Sugamo Prison. Following his release on Christmas Eve of 1948 – coincidentally one day after former Prime Minister Hideki Tojo and six other convicted war criminals were executed there by hanging – Kodama donated some of the huge assets he had repatriated from China to establish the Liberal Party, the predecessor of today’s ruling Liberal Democratic Party.
Afterwards, Kodama became known as a fixer, not only in the realm of politics, but also with the latent power to influence rightist groups, underground criminal syndicates and corporate racketeers. The source of his power was his ability to intimidate people. Kodama targeted errant individuals based on information he’d obtained from the underworld, and sometimes delegated rightists or gangsters to attack them, thereby insulating himself from legal ramifications.
Declassified U.S. government documents, produced just after the war and obtained by this author, contained details of an episode concerning Kodama.
Four days after he was released from prison, on December 28, 1948, Kodama sent a proposal to the Supreme Commander for the Allied Powers. He indicated he had a supply of radium material that he wanted to present for the benefit of the occupation. Later he handed over three lead receptacles, which held needles and tubes containing radium.
The Supreme Commander, however, was wary of the radium's source. It was suspected the material had been looted by the Kodama Agency from foreign countries during the war, and the Civil Property Custodian (CPC) was requested to investigate its origin. Their findings were as follows:
On August 20, 1945, five days after Japan surrendered to the allied nations, Takeo Tada, vice minister of the Japanese Imperial Navy, came to an agreement with Kodama. The Navy owed money to Kodama, and wanted to settle the debt by providing him with radium. At that time in Japan, radium, used mainly for producing luminous paint, was a costly material even more valuable than diamonds.
The declassified U.S. document stated: “At the close of the war, the Japanese Navy found itself entirely destitute, without funds to pay its debts or its employees and, therefore, it made payment in supplies and property. Mr. Tada stated that Mr. Yoshio Kodama, who had loaned the Japanese Navy the sum of two million five hundred thousand yen, was repaid with a quantity of radium that had been in the custody of the Japanese Naval Medical College.
“Mr. Tada stated he did not know the value or the amount of radium presented Mr. Kodama, but believes the lot to have been extremely valuable because of its weight.”
As it turned out, some of the radium Kodama received from the Japanese Navy originated from Nippon Yako.
Nippon Yako Toryo Seizosho (Nippon Noctilucent Paint Co Ltd) was established in Kyoto in 1924 by Akibumi Fujiki and produced luminous paints. By the 1930s, the company had expanded its relationship with the Japanese military and moved to Shinagawa in Tokyo. Fujiki, considered as a pioneer of Japan’s luminous paint industry, was a capable businessman and successfully grew Nippon Yako into the largest manufacturer in its field.
To some, the link between luminous paints and the Japanese military might seem puzzling. During time of war, however, radium was one of the strategic commodities that could determine the course of battles. When aircraft or naval ships operated secretly at night, luminous paints were put on the instruments of cockpit and bridge, enabling pilots and crews to maneuver by means of the dim green illumination they afforded.
But radium did not occur naturally in Japan, so the country had no alternative but to source it from abroad. The Supreme Commander later questioned Fujiki of Nippon Yako about his business.
Fujiki stated that his company imported radium from Eldorado Gold Mines Ltd, a
Canadian company, at the request of the Japanese navy. Transactions were
carried out through the New York office of Mitsubishi Shoji trading company,
and Fujiki said he believed some of radium Kodama received from the Imperial
Navy originated from the material he had imported from Canada.
A former employee of Nippon Yako also stated that out of concerns over wartime air raids, some of the radium stocks were evacuated from company facilities and buried in the ground for safety. Part of the radioactive material was later recovered and attempts were made to sell it in order to cover employees' living expenses. If that were the case, it’s possible to assume that bottles of radium, discovered beneath the floorboards of the empty house in Setagaya, originated from the company's missing stock.
There is more to this episode.
The radium business of the Eldorado from which Fujiki had purchased the radioactive material had been in decline by 1940.
But Eldorado found a promising new market during the war, not for radium but uranium, once treated as a by-product from the processing of radium, which became a strategic commodity. The Canadian mining company supplied uranium to the top-secret Manhattan Project of the U.S. government, and indeed it was uranium ore from the two mines, in Africa and Canada, that was ultimately used to produce the atomic bombs dropped on Hiroshima and Nagasaki in August 1945.
After the war, the Canadian company, by then taken over by the Canadian government and renamed Eldorado Mining and Refining Ltd and, later, Eldorado Nuclear Ltd, found a new client in resource-poor Japan: Tokyo Electric Power Company (TEPCO), which was trying to switch from thermal to nuclear power generation. In December 1967, TEPCO signed a contract to purchase uranium from Eldorado to operate the newly built Fukushima Daiichi nuclear power plant – then a symbol of hope that became one of despair 44 years later when it suffered a triple meltdown.
The mysterious radium material that appeared in an old empty house in Setagaya shortly after the Fukushima nuclear disaster shed light on a chain of history dating back to before the war: from a Canadian mine to the Japanese Imperial Navy, then to the creation of the atomic bomb and a fixer for underground criminal syndicates and, ultimately, to Tokyo Electric Power.
Eiichiro Tokumoto is a writer living in Tokyo.