The holiday season is upon Japan. Ornamental trees are wearing their straw jackets. Smartly wrapped rice cakes are selling helter-skelter in department stores. Antacid commercials are showing up more often on television and 27 million people are steeling themselves for the ferocious crowding encountered during traditional trips to home towns.

Year's end in Japan brings forth one of the world's most tightly choreographed productions of mass festivity. It begins with "Forget-the-Year" parties, moves on to an entirely secular Christmas and closes with New Year's revelry, Shinto and Buddhist style.

For 10 days, a country known for cherishing work above all else virtually closes up shop. Alcohol consumption soars, family budgets are ruined and the skies over the big cities turn their closest to crystal clear as the smokestacks of industry are turned off.

Hirosuke Katsura, an honorary professor at the Education University at Tsukuba city, sees an almost spiritual significance in these uniquely Japanese events. "It is as if people return to the womb," he says. "They put aside routine activities and sleep soundly. They are revitalized for the entire year."

It all shows that festive tradition is alive and well in industrial Japan. But more and more, young people are ignorant of its culinary skills and deep symbolism. Foods made laboriously at home in former days now come off the store shelf. People display New Year decorations but have no idea what they mean.

When the air turns cold in Japan, the holidays can't be far off. Outside, straw jackets are put over subtropical ornamental trees, imparting a pleasing sculpturesque effect. At home, people fight chills with heating devices that have been electrified and modernized.

They sit at kotatsu, low tables with quilting hanging from the edges. Warm air, once generated by burning charcoal and now by electricity, soothes cold legs. Inside their clothing, people tuck pads that radiate heat produced through a chemical reaction. In the old days, they carried metal boxes with special substances burning smokelessly inside.

On shopping streets, Christmas trees and wreathes (or, increasingly, electronic renderings of them) appear. As the 25th draws near, Santa Claus walks the aisles, the song "Jinguru Beruzu," or "Jingle Bells," plays incessantly on radios and Salvation Army bands puff away on bustling street corners.

On Christmas Eve, young children tear into presents provided by parents trying to be up with the times. Christmas cakes bought on the way home are eaten. With Christians making up less than 1 percent of Japan's 120 million people, there is next to no observance of the day's religious significance. It is not an official holiday.

Another holiday import is Beethoven's choral symphony, the Ninth. Japanese will listen to about 150 live performances of it this year all over the country. It has been a season favorite since before World War II, when the national radio orchestra put it on as a year-end treat to arrest flagging attendance.

Amateurs flock to perform the exhilarating "Ode to Joy" chorus of the final movement with professional orchestras. "It fits the mood of Japanese who want to close the old year in a sincere mood and welcome the new one with happiness," says Takatsugu Kuwahata, an administrator with the Yomiuri Nippon Symphony Orchestra, one of nine in Tokyo. It is doing eight such performances this year.

By mid-December, Japanese New Year's symbols are appearing. Three rods of bamboo, swathed in straw and pine branches and placed at doorways, are common. So too are elaborate assemblages including shrimp, oranges and rice cakes. Each item is packed with symbolism, conveying such ideas as longevity and prosperity.

In the final days of December, people begin traveling, since returning to one's roots is held to be the essence of New Year. Last season, 27 million hit the road. Japan becomes a great traffic jam. Planes are full. The famous "bullet trains" of Japan are packed, with people stretched out on floors and doorways.

New Year's cleaning gets under way. Work crews work over modern suspension bridges and ancient wooden ones. Temples and shrines get scrubbings, too. Women are supposed to do their houses themselves. Some do. Others call one of the many New Year's express cleaning services that have appeared in recent years.

On New Year's Eve, Japan is glued to the tube. Nationally broadcast pop singing draws tens of million of viewers. No countdown is heard at midnight. Instead, bells at temples and shrines around the country are rung, with live television coverage from the most famous or picturesque spots.

Starting at midnight, people go for hatsumode, first visit of the year to a shrine or temple. They clap, throw some coins into the bin and ask Shinto deities for good fortune or whatever. It goes on for three days and last season drew 82 million people. For most it is tradition, not religion.

Inside the walls of the Imperial Palace in Tokyo, Emperor Hirohito greets his government and people. Each year, more than 100,000 people pass through the gates (his birthday in April is the only other time the grounds are open) to cheer or gaze with curiosity when Hirohito appears behind glass and offers a few words.

Postal workers, meanwhile, make the rounds delivering loads of New Year's greeting cards. More than 3 billion cards will be mailed during the season, as it is customary to send to just about everyone with whom you have a significant personal or business relationship.

Some children try out traditional New Year's games, such as tops, kite flying and an ancient badminton in which the loser's face is daubed with india ink.

By the 4th or 5th of January, things are edging back toward normal. But there is a postscript. On the first day of work, this year the 6th, women normally found in western clothes at work show up in fancy kimonos. For one day, the streets of Japanese cities have something of the flavor of times past.