When it comes to saving energy, the Japanese have much to teach the United States and other rich countries, whose leaders descend on Japan next month for a Group of Eight summit.
Energy consumption per person here is about half that in the United States, and the growth of greenhouse gas emissions is slower than anywhere in the industrialized world.
There is a hiccup, though, in this world-beating record. It happens inside the Japanese home, where energy use is surging. And nothing embodies the surge quite like the toilet -- a plumbing fixture that has been reengineered here as an ultracomfy energy hog.
Japanese toilets can warm and wash one's bottom, whisk away odors with built-in fans and play water noises that drown out potty sounds. They play relaxation music, too. "Ave Maria" is a favorite.
High-end toilets can also sense when someone enters or leaves the bathroom, raising or lowering their lids accordingly. Many models have a "learning mode," which allows them to memorize the lavatory schedules of household members.
These always-on electricity-guzzlers (keeping water warm for bottom-washing devours power) barely existed in Japan before 1980. Now, they are in 68 percent of homes, accounting for about 4 percent of household energy consumption. They use more power than dishwashers or clothes dryers.
"For hygiene-conscious Japanese, the romance with these toilets is equivalent to the American romance with the Hummer," said Philip Clapp, deputy managing director of the environmental group at the Pew Charitable Trusts in Washington.
Serious about cleanliness
Toilets with built-in warmers for bottom-washing first arrived in Japan in the 1970s. They were U.S.-made medical devices for hemorrhoid sufferers. But they took off, becoming the most profitable innovation in the modern history of Japanese bathrooms, according to toiletmakers.
The Japanese are serious about cleanliness. The word for clean -- kirei -- is also a word for beautiful. People often sweep the street in front of their house. They remove their shoes upon entering a house. They shower before bathing. They are sensitive to odors. For all these needs, aversions and desires, super toilets fit the bill, as well as catering to the Japanese love of gadgets.
In addition, Japanese houses are often small and, in the winter, chilly. A warm, comfortable, musical and hygienic seat in the bathroom expands living space.
But as with a Hummer, romance with a high-end toilet is not cheap. Luxury models cost up to $4,000 -- plus at least $2.50 a month per toilet in higher electricity bills.
But unlike the Hummer, which few Americans are now buying and which General Motors may soon stop making, romance with toilets continues to bloom in Japan, albeit with the intensive mediation of government energy watchdogs, who have begun to monitor the behavior of the toilet-smitten masses.
The final report of the Electric Toilet Seats Evaluation Standard Subcommittee noted last year that 23 to 30 percent of Japanese men now sit while urinating. They do so, the report said, for comfort and for "prevention of urine splash."
The report also included findings from the Warm-Water-Shower Toilet Seat Council (an industry group) that women urinate eight times a day, with an average on-seat time of 96 seconds.
The government started gathering these details around 2000, when nationwide surveys of electricity use began to show that toilets had become a significant factor in the country's appliance-driven failure to contain energy use in the home.
The Japanese government is struggling to meet obligations under the Kyoto global warming treaty to reduce greenhouse-gas emissions by 6 percent from 1990 levels by 2012.
At the G-8 meeting next month, Japan will be pushing the United States and other member countries to accept mandatory limits on emissions of the gases, which cause global warming.
Since the oil shock of 1973, no industrialized country has been more effective in squeezing more affluence out of less imported energy than Japan, experts say. Relative to its economy, Japan consumes only a third as much oil as it did 35 years ago.
Industry has led the charge, more than doubling output while using less energy than it did in 1973. To make a ton of steel, Japanese manufacturers use 20 percent less fuel than their counterparts in the United States and 50 percent less than those in China.
The primary reason for efficiency gains was lack of choice. Japan is an export-dependent manufacturing economy with virtually no domestic sources of fossil fuel. In industry, fierce global competition helped compel the profit motive to marry energy efficiency.
No such shotgun marriage, however, has taken place in the Japanese home, where energy consumption has jumped by 213 percent since the 1973 oil shock. Government figures have shown that household power use has risen at almost exactly the same rate as personal spending. (Despite the rise, per capita residential emissions of greenhouse gases in Japan are only 41 percent of those in the United States.)
"Consumers won't sacrifice comfort for the sake of energy conservation," said Yasuhiro Tanaka, chief of the energy efficiency division at the agency for natural resources and energy. "Consumers won't follow that path because we are richer."
Squeezing manufacturers
Since the government cannot stop affluent consumers from buying flat-screen televisions and super toilets, it has chosen to squeeze manufacturers, requiring them to meet increasingly strict energy targets.
In the toilet industry, progress has been impressive, with nearly every manufacturer meeting its 2006 energy-efficiency target, according to government surveys.
Toto, Japan's largest toiletmaker, says that in the past decade, it has cut the monthly cost of electricity for its multi-featured toilets from $4.69 to $2.59. Almost all of this reduction has come without the involvement of toilet users, according to Kazumi Kasahara, a Toto manager.
"We have not heard about customers who turn their toilets off because they want to be green," he said. "What we do hear about are customers who get addicted to these toilets and cannot stop using them."
For the addicted, Toto and other manufacturers -- with government encouragement -- have invented the intelligent toilet.
After a few days on the job in a household, it memorizes when and how family members do their business. Then, with history as its guide, the toilet intermittently heats up its seat and warms its water.
When no one is likely to be in need, the toilet is cool.
Special correspondent Akiko Yamamoto contributed to this report.