Former prisoners of war who turned their backs and whistled Colonel Bogey as the imperial motorcade proceeded down the Mall drew attention to the unresolved issue of an official Japanese apology for the war and for the suffering of the PoWs, some of whom are demanding reparations of pounds 14,000 each.
In fact, the Emperor has gone as far to apologise as the Japanese constitution will allow him, and it has been made clear that he will not go further during this visit. He has on various occasions commented that "I feel deep sorrow [about the war]" and last week, at a press conference in Japan, said that he "would like to understand the suffering of the people [the PoWs]" - tantamount to an apology in Japanese terms.
But it is not his job to make known his personal views. Like the Queen, he is supposed to be above politics; and the concept of "politics" in Japan encompasses far more than it does in Britain. What the PoWs really want is not the Emperor's personal apology but an official apology from the Japanese people, as embodied in the person of the Emperor. The complexities of Japanese politics are such that that is extremely unlikely to happen.
Britain and Japan are very similar in an extraordinary number of ways. Both are small island nations with a weight of tradition, a long history and a monarchy which is supposed to embody the state. Both now are engaged in debate on what exactly the role of that monarchy should be. How is it possible to retain the necessary grandeur and mystery to give the monarchy a meaning and also ensure enough accessibility to make it "relevant"?
In Britain in recent years the monarchy has gone through an unprecedented crisis. Fifty years ago, when Edward VIII abdicated, the media maintained a respectful distance, withholding the news of the King's affair with Mrs Simpson until it could no longer be concealed. The Japanese media behaves in a similar way today. But in Britain the efforts of the royal family to make themselves interesting and accessible have turned their lives into a soap opera played out on the public stage. Criticism of the Queen's finances have meant that she now pays taxes, though in fact up until Victorian times the monarch did contribute to the public purse. There has been considerable debate about whether we need a monarchy at all, although this has quietened with the death of Princess Diana, not so much out of reverence as the realisation that the monarchy and all the pomp associated with it is a crucial tourism asset.
Like the Queen, Emperor Akihito is a constitutional monarch. In fact, according to the post-war Japanese constitution dictated by the American occupiers, he has even less power than the Queen. But look into the background a little, and the situation becomes more complicated.
Akihito was 11 when the Second World War ended. It is said that his father, Emperor Hirohito, wept when he broke the news to his son that, to quote the immortal words he used to the Japanese public, "the war situation has developed not necessarily to our advantage". Under the bene- volent dictatorship of the American occupying forces, Akihito studied under an American tutor, went to a normal school (normal-ish - the Japanese equivalent of Eton) and visited Britain for the Queen's coronation. He was the first Japanese Emperor to be considered a mere human being; his father had begun life as a living god, the direct descendent of the Sun Goddess, and only renounced his divinity after the war.
It was the culmination of all this when he met and fell in love with a commoner - Michiko Shoda, the daughter of a flour-mill tycoon, whom he met on a tennis court. Previous Emperors had always married into the aristocracy. Akihito's love story was the fairy-tale romance of its day, his wedding every bit as splendid and celebrated as Charles and Diana's. Far from being sequestered within the palace, his two sons were sent abroad to study, at Merton College, Oxford.
When Hirohito died in 1989 at the age of 87, the whole of Japan closed down. People queued to sign their names in the books of condolence at the imperial palace, but for many modern Japanese youth, it was an excuse for a few days off - a sign of the ambivalence with which the Japanese regarded the imperial family. Everyone hoped and anticipated that with the accession of the new emperor, the past would be left behind. Akihito had not been tainted by the war; he was not a so-called living god but a modern man, a new monarch for a new Japan.
In the past, the emperors remained very much out of sight within the imperial palace. Akihito still has nothing like the workload of the Queen, who carries out an exhausting round of foreign tours, protocol and ceremony; but he is far more of a modern monarch than his predecessors ever were. Together with Empress Michiko, he receives ambassadors, goes on foreign visits and tours disaster areas. He went down on his knees to comfort the victims of the Kobe earthquake, something Hirohito would never have dreamt of doing.
The imperial couple were present at the recent Winter Olympics in Nagano, where it was noted that the Empress joined in a Mexican wave, swaying along with the crowd. Akihito has even been known to touch his subjects - he recently massaged the shoulders of an elderly man, an act so extraordinary that it was widely reported. From a British point of view it is all familiar, reminiscent of Prince Charles's meeting with the Spice Girls and other royal efforts to fraternise with the hoi polloi. But from a Japanese perspective, it is quite extraordinary.
Modern man or not, when the Emperor was crowned he went through the daijosai ceremony in which he communes with the Sun Goddess and walks "between heaven and earth", thus, as far as traditionalists are concerned, becoming a semi-divine being. A large part of his job as Emperor is to worship and perform rites at various shrines within the palace grounds. The aim of all this pomp is to reinforce the authority of the imperial system by stressing its roots in the distant mythological past. Yet strangely enough, as with the ritual which surrounds the British monarchy, most of it was invented as recently as the last century.
When Algernon Mitford (ancestor of Nancy and Jessica) encountered the Emperor Meiji around 1855, he saw a youth wearing flowing robes with eyebrows shaved and painted in on his forehead, rouged cheeks, lips painted red and gold and blackened teeth. Ten years later, Meiji was a constitutional monarch on the Western model, with a military uniform and a smart moustache. Up until then many Japanese had barely known that the emperor existed. He was a kind of shaman, sequestered in the imperial palace in Kyoto, whose job was to conduct rituals to appease the gods and to give credibility to the shogun or whoever really exercised power at the time.
In 1868, when (with British help) some samurai overthrew the shogunate and set about modernising Japan, they in turn needed the emperor to give them legitimacy. He moved to Tokyo, shrines were built, rites and rituals invented, and the whole paraphernalia of state Shinto was put in place, asserting his descent from the Sun Goddess through an unbroken line. In reality, he had no more power than before.
Japan's 19th-century leaders even made a trip to the West to see how European monarchs did things, noting, for example, that "the marriage ceremonies of the royal houses and families are usually religious" (to quote A Survey of the English Monarchy's Practices, published in 1900). Similarly, many of Britain's traditions, such as the Christmas tree, were imported by Prince Albert from Germany.
Little by little, the role of the Emperor has changed and developed. In 1921 Hirohito came to Britain, where he played golf with the future Edward VIII, the first Emperor ever to travel abroad. He travelled incognito on the Paris metro and always treasured the ticket he bought; it was the only period of freedom he ever enjoyed, and he always said his time abroad was the happiest of his life. Until he announced on the radio that Japan had been defeated, Japanese people had never heard his voice.
Akihito has gone a long way towards creating a modern monarchy in Japan - so much so that the usually deferential Japanese press has even been known to print irreverent articles (though usually they reserve their scurrilousness for the antics of the British royals). No doubt when he meets the Queen, the two will have plenty of ideas to exchange on the role which the ancient institution of monarchy has to play in the modern age.
Lesley Downer is a writer and journalist who has published nine books and presented a television series on JapanReuse content