TOKYO, NOV. 9 -- Amid antique pomp and gilded splendor, Japan's Emperor Akihito will formally take his throne here Monday, acceding to a monarchal seat that is the oldest on Earth -- and yet, completely new.

By an official reckoning that dates back to the misty reaches of proto-history, Akihito will be the 125th occupant of the Chrysanthemum Throne, the world's oldest hereditary regime. But as the first to be enthroned under the post-World War II constitution imposed on Japan by the American occupation, Akihito is a new kind of sovereign, a "symbol of the state" devoid of power.

When his father, the late emperor Hirohito, completed the same enthronement ceremony 62 years ago, he was venerated as a high priest-king-generalissimo, an awesome figure who rode a white stallion before a populace that was forbidden to aim a camera, or even an eye, toward his august presence.

One generation later, Akihito routinely sits cheek by jowl with his countrymen in downtown traffic jams as his black limousine carries him on official duties that range little beyond sipping tea with visiting dignitaries and snipping ribbons at new parks and libraries.

The striking diminution of the emperor's role may explain the indifference most people here are showing toward the $95-million enthronement extravaganza. To be sure, some Japanese are fascinated with the process, while some are furious -- so much so that a threat of violence by anti-royalist radicals hangs over the intricate planning of events.

But most of Akihito's 123 million subjects have responded to their emperor's rite of accession with a collective shrug. Trains bound for resort areas are sold out all weekend. Video rental shops have put out special sign-up sheets so customers can reserve movies for Monday, when regular TV will be preempted by coverage of the ceremonies.

Asked how he plans to spend the national holiday honoring the enthronement of his country's first new emperor since 1928, Kazuhiro Sato, a teacher in the northern city of Noshio, said, "Well, it's a day off, but there's no way I'll go to a pachinko {pinball} parlor. They'll be jammed all day."

Japan does seem interested in the official visitors -- including Vice President Dan Quayle -- from 153 nations who will gather for the enthronement and the associated banquets and tea parties. The burning issue in the popular magazines is the impending meeting between Britain's Princess Diana, who will accompany her husband Prince Charles to the ceremony, and Princess Kiko, the 23-year-old Japanese royal with a smile about as dazzling as Diana's.

But this thriving archipelago is so rich, so important and so confident today that the Japanese people may feel that they no longer need an emperor to look up to.

This is a country, after all, which picked itself up from utter devastation in the shambles of World War II and within four decades became a global economic power with the world's highest per-capita income, largest foreign-aid budget, and second-largest economy.

"Japanese people today, particularly young people, no longer have an inferiority complex toward the world," said Seizaburo Sata, a professor at Tokyo University.

In many ways, Akihito is perfectly suited to this self-assured and proudly democratic country. An amiable, unassuming 56-year-old who favors smartly tailored double-breasted suits of banker's gray, he is a ready conversationalist either in English or in everyday, idiomatic Japanese, unlike prior emperors who generally employed an exotic court language unintelligible to common folk.

The emperor seems fully at ease with his status as a powerless symbol, and has made it clear that he strongly supports the constitutional limit on imperial sway. Left with few official chores outside of the purely ceremonial, he has taken up the cello, played an active role in raising his three children and written several ichthyological monographs on a fish species called the Gobiidae.

Akihito actually has been Japan's emperor since the moment of his father's death on Jan. 7, 1989, and that day marks the official start of his reign, which is known as the Heisei, or Achieving Peace, era. But for reasons that reach back a score of centuries to the earliest chapters of Japanese history, he could not officially complete the ceremonies of accession until this month.