Emperor celebrates 20 years at the throne

Tokyo: Japanese Emperor Akihito commemorated the 20th anniversary of his reign yesterday, but with no notable plans other than a trip to his father's grave.

The anniversary comes as Akihito, 75, has cut back his official duties due to an irregular pulse and bleeding from his stomach, symptoms imperial doctors have attributed to "mental stress."

He has also undergone surgery and treatment for cancer.

The imperial couple had no special plans to mark yesterday's anniversary other than their annual visit to his father's grave, palace officials said.

Akihito ascended the Chrysanthemum Throne after his father, Hirohito, died on January 7, 1989.

Hirohito reigned when Japan invaded Asia in his name during the 1930s and 1940s, during the Second World War.

His responsibility for wartime atrocities committed by Japanese troops remains a major topic of historical debate.

Akihito and his wife, Empress Michiko, bowed before Hirohito's grave, located in Hachioji city in western Tokyo.

Prime Minister Taro Aso also joined the solemn Shinto ceremony there.

On his birthday last month, Akihito assured the nation his health was improving.

Though no longer revered as living gods, members of the imperial family live tightly regimented lives and have been known to suffer from several stress-related illnesses.

Akihito's 45-year-old daughter-in-law, Crown Princess Masako, withdrew from most of her official duties and appearances several years ago because of a nervous disorder. Empress Michiko, 74, has also often complained of stress and suffered a breakdown in the early 1990s that rendered her unable to speak for months.

Succession concerns are also believed to be a major source of worry for the royal family.

Under a post-World War II law, only males can be allowed to assume the throne.

Crown Prince Naruhito, who is Masako's husband and the eldest son of Akihito, is next in line to succeed the ailing Akihito, but they have no sons of their own.