"The tournament will be cancelled over my dead body," said Dewanoumi, and with a body his size, it was a threat to be taken seriously. As a former yokozuna - a champion sumo wrestler - the chairman of the Japan Sumo Association is a man of considerable bulk. Yesterday he was using every ounce of it to reject an outrageous suggestion: that the mighty sumos are lending implicit support to French nuclear testing.
The controversy has been sparked by a three-day sumo tournament scheduled to take place in Paris next month. Forty wrestlers, with a retinue of 80 officials, translators and apprentices, will travel to France for a three-day competition at the Bercy stadium, similar to the sell-out British tournament at the Albert Hall in 1991.
It comes at a time of considerable strain in Franco-Japanese relations. Since President Jacques Chirac's decision to resume nuclear testing, Tokyo and Paris have pursued an increasingly irritable diplomatic dialogue, which climaxed in the visit to Tahiti this month by the Finance Minister, Masayoshi Takemura, and the detention of two protesting Japanese MPs on board a Greenpeace yacht.
Peace groups, business leaders and a chorus of diplomats and politicians have condemned the tests. Last month the novelist Kenzaburo Oe, winner of last year's Nobel Prize for Literature, decided not to go to a French cultural festival.
Anti-nuclear groups have urged the Sumo Association to do likewise, and today spectators at the Autumn Grand Tournament in Tokyo will be greeted by groups of demonstrators.
But the custodians of the so-called "National Accomplishment" are unmoved. "It's not as if diplomatic relations have been broken off, and the tournament has no connection with the French government. We don't want sumo to stick its neck into political issues," said chairman Dewanoumi.
The sumo saga highlights a curious aspect of Japan's reaction to the French tests: despite universal verbal condemnation, very little action has been taken. When President Chirac first made his announcement that France would resume testing, in the run-up to the 50th anniversary of Hiroshima and Nagasaki, there were immediate calls for a boycott. But the government quickly distanced itself from the idea.
French exports to Japan last year amounted to 25.4bn francs (pounds 3.3bn), many of them in mineral water, food, wine, and brand-name perfume, cosmetics and clothes. The evidence so far is that little real harm has been done to the trade figures.
Even among those retailers who have taken firm action, principled idealism is tempered with pragmatism. Bic Camera, a discount store specialising in electrical and household goods, is one of the few chain outlets to discourage its customers from buying French ties, wines and handbags. But they are still on sale - at least until stocks are exhausted.
Despite the two nuclear tests carried out by Peking this year, Chinese- manufactured goods, which make up a large proportion of Bic's television sets, cameras and electrical products, are not subject to sanction.