New Japanese emperor Naruhito, known as an earnest man with a passion for water conservation, is set to formally take up the post on Wednesday, a day after his father gave up the throne in the country’s first abdication in two centuries.

Former Emperor Akihito and Empress Michiko stepped down on Tuesday after three decades as the nation’s top royals in a brief, simple ceremony, with Akihito thanking the people of Japan and saying he prayed for peace.

Naruhito, 59, technically succeeded his father just as Tuesday became Wednesday but his ascension to the Chrysanthemum Throne will be formalized in a mid-morning ceremony, the first part of which his wife and other female royals will not be able to attend.

Naruhito, the first emperor born after World War Two and the first to be raised solely by his parents, said on his birthday in February that succeeding his father “makes me solemn”.

Given the backgrounds of Naruhito and his wife, Masako, a 55-year-old former diplomat - which include extended experience studying and living overseas - hopes are high that they may be more international in their outlook and closer to the lives of many Japanese.

“The curtain has gone up on a new era that will be filled with hope,” said Hiroshi Takahashi, 78, outside his ‘wagashi’ traditional Japanese sweets shop.

“The new emperor has an admirable personality and I hope he creates a fine royal household that expresses his own personality,” he said.

The last imperial succession in 1989 took place during mourning for Akihito’s father, Hirohito.

This time the mood is more festive. Japan has been draped in banners welcoming Reiwa - the name of the new era for Naruhito’s reign - during an unprecedented 10-day holiday. Countdown events were held on Tuesday night in clubs throughout the nation, with people cheering as the clocked ticked down to midnight and fireworks shooting into the sky in some areas.

On Wednesday morning, electric signs in Tokyo’s subway system bore messages “congratulating the emperor on his accession” and workers in a downtown Tokyo electronics store wore red shirts saying “Happy New Era Reiwa.”

In the first stage of Naruhito’s accession ceremony, imperial chamberlains will put the state and privy seals, along with cases containing two of Japan’s “Three Sacred Treasures” - a sword and a jewel - on desks in front of him as proof of his rightful succession.

It will be observed by a small group including adult male royalty and representatives of the three branches of the government, including Prime Minister Shinzo Abe and his cabinet.

Akihito and Michiko will not be present, but Satsuki Katayama, the only woman in Abe’s cabinet, will become the first woman in modern history to attend.

After that, female royalty will enter the room and Naruhito will make his first public remarks as emperor. His formal enthronement will take place at a more elaborate ceremony in October attended by dignitaries from Japan and around the world.

Naruhito’s passion for water conservation dates from his study of medieval transportation and includes an interest in other environmental topics. Masako has expressed an interest in topics related to children in trouble or living in poverty.

Though Masako struggled with a stress-related illness described by palace officials as an “adjustment disorder” that kept her largely out of the public eye for years, her public appearances have recently increased.

Their only child is a daughter, Aiko, 17, who cannot inherit the throne. Naruhito’s heirs are his younger brother, Prince Akishino, followed by Akishino’s 12-year-old son, Hisahito.