Japan's Emperor Akihito will step down on March 31, 2019, a report said Friday, the first imperial retirement in more than two centuries.
Prime Minister Shinzo Abe will meet top officials and members of the royal household next month before announcing the date, the Asahi Shimbun reported, citing unnamed government sources.
Akihito's eldest son, 57-year-old Crown Prince Naruhito, will ascend the Chrysanthemum Throne the next day on April 1, the paper said.
The popular 83-year-old Akihito shocked the country last year when he signalled his desire to take a back seat after nearly three decades, citing his age and health problems.
There have been abdications in Japan's long imperial history, but the last one was more than 200 years ago.
Akihito's unexpected move presented a challenge since there was no law to deal with an emperor retiring from what is usually a job for life -- and it reignited debate about allowing women to ascend the traditionally male-only throne.
In June, the parliament passed a one-off rule allowing the ageing emperor to step down but the Asahi report is the first time a precise date for the abdication has been mooted.
"It is an immeasurable relief to me that his majesty ... can now have days of rest as he reaches an advanced age," Empress Michiko, who turned 83 Friday, said in a statement.
The status of the emperor is sensitive in Japan given its 20th century history of war waged in the name of Akihito's father Hirohito, who died in 1989.
Some worried that changing the rule to allow any emperor to abdicate could put Japan's future monarchs at risk of being subject to political manipulation.
"Nothing has been decided on this issue," a spokesman for the Imperial Household Agency told AFP, declining to comment further.