Empress Michiko, a wealthy flour magnate's daughter, was the first commoner in modern times to marry into Japan's imperial family.
Following their fairy-tale wedding in 1959, Michiko, now 79, also became the first empress to raise her children herself, famously making them "bento" lunch boxes to take to school.
"Being an emperor can be a lonely state," Akihito said in an interview released by the Imperial Household Agency on today.
"And I feel most fortunate that I have been able to endeavour to carry out my role as emperor with the empress by my side," said the ageing monarch, who inherited the Chrysanthemum Throne in 1989 upon his father Emperor Hirohito's death.
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The soft-spoken monarch greeted well-wishers from a glass-covered balcony at the Imperial Palace overlooking the East Garden, flanked by Empress Michiko and other members of the royal household.
"Thinking about disaster sufferers, I will spend my days wishing all the people happiness," he said, referring to the devastating 2011 earthquake and tsunami and various other natural disasters that struck Japan in the past year.
In the afternoon, Prime Minister Shinzo Abe joined other dignitaries for a birthday banquet at the palace.
While Emperor Hirohito was once worshipped as a living demigod, Akihito and Michiko have tried to be seen as an "ordinary couple" and narrowed the distance between the palace and the people.
The Imperial Palace, surrounded by stone walls and mossy moats - is opened to the general public twice a year - on the emperor's birthday and the second day of New Year - for the royal family to greet well-wishers.