TOKYO (REUTERS) - Cheers and screams filled the air in Tokyo on Saturday (May 4) as new Japanese Emperor Naruhito and Empress Masako made their first greetings to an ecstatic public three days after acceding to the throne following the first abdication in two centuries.

Emperor Naruhito's father, Emperor Emeritus Akihito, 85, abdicated on Tuesday in a simple ceremony, nearly three years after he first expressed fears that advancing age might make it difficult for him to perform his duties. It was the first abdication in 200 years.

Pledging to work as a symbol of the people, Emperor Naruhito, 59, was formally invested as emperor the day after.

People queued for hours to see the new emperor and his family stand on a palace balcony and wave to the gathered crowds. Normally such greetings take place during the New Year's holiday and on the emperor's birthday.

"I pray for your health and happiness," said the Emperor, reading prepared remarks. "And I sincerely wish for further development of our nation by going hand in hand with other nations and seeking global peace."

Empress Masako, wearing a yellow dress and hat, waved and smiled to the crowds along with other imperial family members.

They will greet the crowds six times on Saturday, according to public broadcaster NHK.

Akihito became emperor in 1989 after the death of his father, Emperor Hirohito, which set off an extended period of mourning throughout Japan, but the mood has been completely different this time.

Clubs held countdowns on Tuesday night, fireworks rocketed into the air and stores held special sales to honour Reiwa, the era name under which Naruhito will reign. Hundreds of couples rushed to city offices to register their marriage.

The festive mood, which many compared to New Year's, has been fed by an unprecedented 10-day holiday that observers expect will bring an economic boost to Japan's sluggish economy.