There is currently no constitutional allowance for Japanese Emperor Akihito to resign

Health concerns have led Japan’s Emperor Akihito to address the nation for only the second time in his reign, setting the stage for his possible abdication after 28 years.

In a rare, pre-taped video broadcast on Monday, the 82-year-old head of the world’s oldest monarchy discussed his willingness to consider resignation – an act for which there is no precedent in modern Japan and no existing legal pathway.

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Akihito is the son of Emperor Hirohito (now called Emperor Showa), who ruled Japan during World War II – although his role in the war remains contested among historians to this day.

Akihito battled prostate cancer in 2003 and underwent heart surgery in 2012, The New York Times reports.

“I am concerned that it will become more and more difficult for me to fulfill my duties as a symbolic emperor,” he explained during the ten-minute address.

Given the constraints of office, the Emperor’s address, largely couched in diplomatic language, constituted “a sharing of his thoughts” with the nation.

Large among “hypothetical” points he raised in his address to the nation was what would happen if the Emperor were to become “too frail to perform his constitutional duties.”

Raising the possibility of establishing a regency, Akihito also suggested that the traditional one-year period of mourning is too long and too impinging on the succession.

Under Japanese law, there is no constitutional allowance for abdication, with the throne passing only due to an Emperor’s death.

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Despite its often vague diplomatic language, Akihito’s orchestrated speech directly addressed key concerns that have plagued Japan’s royal household in recent years.

Late last month, Japan’s public broadcaster NHK reported that the Akihito was seeking a way to abdicate in favor of his eldest son, 56-year-old Crown Prince Naruhito.

In a brief response to the Emperor’s address, Japanese Prime Minister Shinzo Abe told reporters that “the government would now have to have thorough discussions.”

Akihito and Empress Michiko have three children.

Akihito’s abdication and Naruhito’s succession, however, will not end Japan’s Imperial crisis.

Naruhito and wife, Princess Masako, a Harvard educated diplomat have only one child, a 14-year old daughter, Aiko – and the current Imperial Household Law prohibits women from succeeding to the Chrysanthemum Throne.

Abdication by a reigning emperor has never occurred in modern Japan.

The current royal household traces its line of succession to the Meiji Restoration in 1868 – and arguably, 2,500 years before that, with the last abdication by a Japanese emperor technically occurring 200 years ago.

Emperor Akihito succeeded his father, the Emperor Hirohito in 1989. Hirohito came to the Crysantheum Throne on Christmas Day in 1926 and was initially revered as a living god. After World War II, the Empreror’s role in national affairs was constitutionally limited to a largely ceremonial status under U.S. occupation.

Before abdication could occur, the Japanese Parliament would need to revise the Imperial Household Law.