TOKYO (AP) _ Japan's imperial family and top government officials marked the first anniversary Sunday of Emperor Hirohito's death with ceremonies at the Imperial Palace and the late monarch's tomb.

The anniversary ended an official one-year mourning period for the royal household, permitting in the coming months the marriage of a prince and the elaborate coronation of Hirohito's son, Emperor Akihito.

Early Sunday, Akihito and Empress Michiko presided over a quiet ceremony at an Imperial Palace chamber where, by tradition, an emperor's spirit is enshrined until his tomb is completed.

About 115 guests, including Prime Minister Toshiki Kaifu and leaders of Parliament, attended the rite, during which Akihito read a short prayer for his father's soul. The Empress Dowager Nagako, 86, did not attend because of hip and back problems.

Another ceremony was to be held later in the afternoon at Hirohito's tomb. Construction of the dome-shaped mausoleum in suburban Tokyo was completed Saturday at a reported cost of $18.5 million.

Hirohito died of cancer Jan. 7 last year at the age of 87. His 62-year reign was the longest in Japanese history, and covered a difficult period of militarist adventurism, defeat, foreign occupation and rapid economic reconstruction.

Under the postwar constitution, the emperor is a symbolic figurehead who performs mostly ceremonial functions.

Akihito assumed the throne immediately after his father's death, but his official coronation will not be held until November. In a draft budget for the fiscal year beginning April 1, the government earmarked $58 million for the enthronement and related ceremonies.

Prince Aya, who at 24 is Akihito's youngest son, will wed college sweetheart Kiko Kawashima on June 29. Aya is second in line to the Chrysanthemum Throne.