Japanese investors have been buying most of France's government debt recently in a record surge spurred by expectations that Europe faces the kind of deflation and growth that Japan suffered for decades.
Since the European Central Bank (ECB) signaled in May it would take radical steps to ease monetary conditions, banks and other big investors in Japan have piled into French bonds, convinced from their own experience that the debt of a country where the central bank is battling deflation represents a winning bet, market participants say.
"In a way, they are expecting Japanisation - deflation and a long period of zero interest rates," said Hiroki Shimazu, senior market economist at SMBC Nikko Securities.
Japanese investors bought a net 1.9 trillion yen (14 billion euros) of French bonds in May, equal to more than 60 percent of the government's new issuance that month, Japanese Finance Ministry data shows.
Data is not available for June, but market participants say Japanese buying of French bonds has picked up from May amid a broader increase in buying of euro-zone debt. One suggested Japanese investors may have bought the equivalent of three-fourths of the French new issuance.
French bonds represents a Goldilocks trade for Japanese investors keen for euro-zone exposure: they yield more than German bonds, while lower credit ratings on Italy's bonds - the region's third-most-liquid market - deter active Japanese buying.
On a gross basis, Japanese investors bought 6.60 trillion yen ($65.2 billion) of French government debt in May, dwarfing last year's 1 trillion yen average and by far the most since the ministry began compiling such data in 2005.
While the euro zone's financial crisis has seen spikes in market interest rates as bond prices plunged, Japanese investors have strong memories of a completely different dynamic.
As Japan suffered years of falling prices and tepid growth, the government's bond market proved one of the world's great long-term bull markets.
Having slashed interest rates to zero during this period, the Bank of Japan invented the now globally recognized idea of "quantitative easing" - mass purchases of bonds and other debt to inject cash into the economy.