Akihito's possible abdication requires a change in the Japanese constitution which says an emperor serves until death.

Japanese Emperor Akihito said he is worried that his age and declining health would make it difficult for him to fulfill his duties, in a rare video address to the public on Monday.
"I am already 80 years old, and fortunately I am now in good health. However, when I consider that my fitness level is gradually declining, I am worried that it may become difficult for me to carry out my duties as the symbol of the State with my whole being as I have done until now," he said.

The 82-year-old monarch, who has had heart surgery and received cancer treatment, said that sometimes he feels "various constraints" in his physical fitness. He, however, suggested the idea of appointing a regent who would be able to carry out the duties the emperor is not specifically able to to do. "It is conceivable that a regent could be appointed," he said.
Akihito is the 125th emperor of Japan who ascended to the Chrysanthemum throne after his father Hirohito died in 1989.
The Imperial House of Japan is the oldest continuing hereditary monarchy in the world.

Akihito did not explicitly say he wants to step down and never used the word ‘abdication.' However, his remarks were interpreted as a verification of previous reports that Akihito wanted to hand over his duties.
The Emperor's 10-minute-long pre-recorded message was allusive as he did not want to be seen as interfering in politics.
Japan's 1947 post-war constitution defines the Emperor as "the symbol of the state and of the unity of people", a figurehead with no political power.
Under the constitution, the emperor is not allowed to make any political statements.

This was Akihito's second time to speak directly to the nation. The first one was in 2011, when an earthquake and tsunami devastated the northeast coast of Japan causing a nuclear disaster in Fukushima.
Opinion polls suggest that the vast majority of ordinary Japanese sympathise with Akihito's potential abdication. However, this requires a legal change in Japanese law which says an emperor serves until death.

In a swift response to the emperor's statement, Japanese Prime Minister Shinzo Abe said his government will take the remarks "seriously," without making any specific commitment.
"Considering the emperor's duties, as well as his age and the burden [of the job], we have to firmly look at what we can do," Abe stated.
If Japanese parliament changes the law to permit Akihito's abdication, he would become the first emperor in two centuries to leave the throne.
The last Japanese monarch to step down was Kokaku, who gave up the throne in 1817.