Renoirs, Picassos, Monets, Cezannes and Van Goghs, bought in a spending spree that drove prices spiralling upwards, have been mothballed because billions of yen have been wiped off their owners' personal wealth, and they are unable to service the loans taken out to buy the paintings.
Renoir is the single most popular Western artist in Japan. Hundreds of his paintings were snapped up in the late 1980s by Japanese investors.
Some were acquired by art lovers, but most were bought by speculators who saw millions of yen in profits to be made from his studies of bathers or voluptuous females in pools of light. According to one art critic, Japan acquired one-sixth of the 6,000 oils and watercolours Renoir painted.
But many of the canvases are now gathering dust in darkened warehouses, inaccessible to all. They have been kidnapped by Japan's gloomy economic recession.
Japanese speculators bought nearly pounds 10bn of Western art during the easy credit days of the economic boom. The sudden influx of buyers, hungry for 'big names', saw a wild spiralling of prices and records broken on a regular basis in New York and London, particularly for Impressionist works, and Christie's and Sotheby's began to show in Tokyo for the Japanese market.
Then the Tokyo stock market crashed, bringing many speculators down with it, and the banks began to repossess the now overpriced paintings.
The most extreme case is that of Ryoei Saito, the paper magnate, who in one week in 1990 spent dollars 160m ( pounds 105m) buying Au Moulin de la Galette by Renoir and Portrait of Dr Gachet by Van Gogh. Mr Saito shocked the art world by declaring that he wanted the two paintings to be cremated with him when he died. Worldwide protests forced him to reconsider, but he had already become a symbol of the apparently mindless acquisition of Western art by speculators who had little appreciation, beyond the price tag, for their purchases.
Now, however, Mr Saito's company, Daishowa Paper Manufacturing, is in trouble. The days when he could buy extravagant art works at will are long gone. The company is undergoing restructuring, his plans to build a special museum to show his collection of Chagalls is on hold, and as he negotiates debt reduction with his banks, there is speculation that he may be forced to sell off his paintings.
Koji Yamada, who works in the Tokyo office of Christie's, estimates that about a quarter of all the paintings bought during the art craze from 1987 to 1990 are now in the hands of financial institutions, who keep them sealed away in safekeeping and allow no one to view them. And they are likely to stay there for a long time, because the inflated prices paid by Japanese investors are not going to return in a hurry.
Last year Japan spent pounds 394m on Western art - little more than one-tenth of the pounds 3.7bn worth imported in 1990 at the peak of the boom. 'The art industry lost credibility with clientsd during the bubble economy,' said Mr Yamada. 'It will be a very slow recovery.'
This is bad news for art lovers. The paintings that have been repossessed by banks are still being held on their books at the cost price, even though today's market prices are substantially lower. The banks will be reluctant to unload them now for a large paper loss: rather, they will continue to store them and hope for a recovery.
'Why do Japanese banks have so many paintings? The reason is simple: they don't want to lose money by dumping them,' said Shinichi Segi, head of the Tokyo Art Institute, a private organisation that follows the art market in Japan.
He describes the frenzied buying of Western art as 'ridiculous'. 'Just a fraction of those buying paintings were art lovers. Most were moneymongers, unfortunately.' Ulitmately, Mr Segi blames the banks for fuelling the excess. 'If they had not lent money for buying paintings, the spiral in prices would not have started.' And more of the reamarkable paintings might be on view, not confined to debtors' prison.
THE ART MARKET'S BURIED TREASURE
VAN GOGH: Portrait of Dr Gachet (dollars 82.5m), part of a private collection belonging to Ryoei Saito, who threatened to burn it.
RENOIR: Au Moulin de la Galette (dollars 78.1m), another painting owned by Saito, which he threatened to burn; A Cocoa- drinking Lady (dollars 18.5m), bought by an unknown investor; it has disappeared. Woman After Bathing and Woman Reading, bought for a reported 3.6bn yen (pounds 22.5m) by Mitsubishi; now in storage after a tax dispute.
PICASSO: Au Moulin Rouge (dollars 8.3m) bought by Yasumichi Morishita, whose firm has fallen into difficulties. Now held by financial institutions in storage. Pierrette's Wedding (dollars 52m) now held in bank storage in Osaka. Acrobate et Jeune Arlequin (dollars 38.4m) also in storage.
MONET: By the Seine (dollars 3.7m), also acquired by Yasumichi Morishita, and now in storage. Waterlilies (dollars 10.3m) is also now held in storage.