Instead of the usual roar of approval from the crowd, the Japanese royals were greeted by a cacophony of protest as their carriages were driven towards Buckingham Palace.
At one point the Prince of Wales leaned forward to make small talk with the Japanese guests in an attempt to shield them from the booing of the ageing protestors.
At a ceremony at Horse Guards, the Emperor and Empress were afforded every courtesy of the official welcome and were able to enjoy the pomp and grandeur without the disruption of demonstratos.
The imperial couple travelled down The Mall with the Queen and Duke of Edinburgh in two closed carriages with windows which would muffle the sounds from noisy demonstrators.
Despite the angry reception, the Queen and Emperor Akihito managed to remain composed when they arrived at Buckingham Palace. They seemed detached from the angry scenes around them, as if nothing was wrong.
The Emperor and Empress lunched with their hosts in the Bow Room overlooking the Buckingham Palace gardens.
After lunch came the controversial award of the prestigious Order of the Garter to the Emperor from the Queen.
War veterans had protested at the award of the honour which was also held by the Emperor's father, grandfather and great-grandfather.
The protesters were back after lunch to await the Emperor's arrival at Westminster Abbey, where he laid a wreath at the Tomb of the Unknown Soldier.
As he and Empress Michiko stepped out of their Rolls-Royce limousine, members of the crowd outside turned their backs and began humming Colonel Bogey.
The Emperor ignored the demonstration as he walked the few steps into the Abbey.
The next stop for the royal couple was a brief visit to St James's Palace, squeezed in before tea with the Queen Mother and the high point of the day - a state banquet at Buckingham Palace. Addressing the guests, the Emperor said he could "never forget" the many kinds of suffering undergone by so many.
He said: "It truly saddens me, however, that the relationship so nurtured between our two countries should have been marred by the Second World War."
His words failed to satisfy the veterans, however, who said their protests would continue long after the Emperor had returned to Japan.Reuse content