Tokyo is now caught in a dilemma: by rapidly expanding its much-criticised whaling programme, Japan now kills more of the mammals than consumers eat.
The result is an unprecedented surplus. Prices - once delicacy-high - are plunging, inventories are bursting, and promoters are devising new ways to get the Japanese to eat whale.
Kunitada Ito, a merchant at Tsukiji fish market in Tokyo, said: "I have to admit, prospects for whale demand don't look good at the moment."
His company, Toshoku, has slashed prices by 25%, but its freezers are still stacked. Toshoku's situation is not unique.
According to the Fisheries Agency, about 1035 tons of the meat hit the market in Japan last year, a 65% increase from 1995. Sluggish demand means inventories have almost doubled in five years to 2704 tons in 2004.
In the same five-year period, the average price of whale plunged almost 30%, to 2560 yen ($21.60) a kilo in 2004.
But the overabundance has not stopped the harpoon guns.
Tokyo plans to kill - under a research programme - about 1070 minke whales in 2006, over 400 more than last year and more than double the number it hunted a decade ago.
Kenji Masuda, a fisheries official, said Japan will also hunt 10 fin whales, and a total of 160 Bryde's, sei and sperm whales.
The International Whaling Commission banned commercial whaling in 1986 but approved limited hunts for research purposes a year later.
Opponents have called Japan's hunts a way for it to dodge the ban.
Tokyo, however, says its programme is needed to establish reliable information on whale populations and habits - data that Japan says can be gleaned only by killing the animals.
A public relations pamphlet Delicious Whales, distributed by the government-affiliated Japan Whaling Association, reads: "Is it OK to eat whale meat? Of course it is."
"Even if we capture 2000 whales a year for 100 years, it's OK because whale numbers are growing," the pamphlet says.
But the association acknowledges whale is a hard sell.
The meat was considered a rich source of protein in the lean years after defeat in the second world war, but people moved on to other meats, notably beef, as they became more affluent.
Some local governments have started to tackle the challenge by promoting whale meat in school lunches.
Wakayama, a prefecture with a strong whale-hunting tradition 450km (280 miles) southwest of Tokyo, has been aggressive in getting youngsters to indulge, introducing whale meals at 270 public schools in 2005.
"To put it simply, whale meat tastes horrible"
Hana No Mai restaurant customer
Nutritionists have developed child-friendly whale dishes, including whale meatballs, hamburgers and whale spaghetti Bolognese, said Tetsuji Sawada of Wakayama's education board.
But it may take a long time to change consumer habits.
Young diners at a Hana No Mai restaurant in Tokyo, one of several low-cost chains adding the increasingly cheap meat to their menus, turned their noses up at the blubber.
Japan fishes Bryde's, sei, fin,
minke and sperm whales
Kosuke Nakamura, 30, said: "To put it simply, whale meat tastes horrible."
Younger people were put off by the tough, pungent meat, while it brought back memories of postwar poverty for older generations, he said.
While few Japanese voice environmental concerns, young people such as Nakamura say it has brought the country unfavourable publicity.
"Whaling's so bad for Japan's image. I don't know why we still hunt," Nakamura said.
Chimney Co, which runs Hana No Mai, acknowledged customers were wary of the new dishes, introduced in November.
Still, officials say Hana No Mai will continue to carry whale meat. A trader at one of Tsukiji market's biggest wholesalers, Daito Gyorui Co, was equally optimistic.
"The fall in prices is a good thing because it will make whale meat more accessible," Yoshiaki Kochi said.
"Japanese will never forget the taste of whale. It's part of our culture. It's in our DNA."