TOKYO (AP) — Japan's beloved former Emperor Akihito marked his 91st birthday on Monday, as he continues to pursue his lifetime research into goby fish, care for his wife and pray for peace.

Akihito, who abdicated in 2019 and handed over the Chrysanthemum throne to his son, Emperor Naruhito, now holds the title of Emperor Emeritus.

Akihito has since receded from official duties and enjoys his time quietly while caring for his 90-year-old wife, former Empress Michiko, who broke her leg bone in October and is still recovering, according to the Imperial Household Agency.

Akihito's daily routine includes reading newspapers in the morning and evening, and watching the news with Michiko over meals, the IHA said.

The former Emperor was to celebrate his birthday on Monday with his relatives and other guests.

This year, Akihito has been particularly concerned about people who were affected by a fatal New Year earthquake and heavy rains in autumn in Japan's northcentral region of Noto, the IHA said.

Akihito continues to actively research the classification of Japanese freshwater goby fish at a palace laboratory and his residence, officials said.

Under Japan’s Constitution, the emperor is a symbol without political power. Wartime militarist governments worshipped the emperor as a living god and fought the war in his name until Akihito's father renounced that status after the country’s 1945 war defeat.

Akihito during his three-decade reign embraced an identity as peacemaker and often made reconciliatory missions and carefully scripted expressions of regret on the war.

Palace officials said Akihito continues to observe a moment of silence on days marking key events of the war, including the end of the Battle of Okinawa, the anniversaries of the U.S. atomic bombings on Hiroshima and Nagasaki and the day Japan surrendered.

The former emperor’s daily life is “still deeply connected with his wartime memories,” the palace said. Akihito and Michiko are currently rehearsing passages from a book on the Battle of Okinawa as part of their daily routine, the IHA said.