Updated

A 12,000-page history of Emperor Hirohito released in Japan on Tuesday includes childhood letters to his parents but steps gingerly around what many want to know: his thinking on issues such as his responsibility for World War II. The record took 24 years to create, but scholars and journalists say it is still incomplete.

The official annals released by the Imperial Household Agency, a tradition dating back 14 centuries, provide a detailed timeline of Hirohito's life but don't appear to shed much new light on a 62-year reign that spanned Japan's brutal invasion of much of Asia and its reconstruction and emergence as a global economic power in the postwar years.

The 61-volume record "hardly contained anything new that reverses conventional wisdom and history," the liberal-leaning Mainichi newspaper said in an editorial. "We must keep asking ourselves why that catastrophic war could not be avoided. ... The question is hardly resolved."

The conservative Yomiuri newspaper noted that the annals left out Hirohito's own words on Yasukuni Shrine, where war dead are deified, and criticized the palace for attempting to avoid trouble.

Instead, the official history cites a 2006 scoop by the Nikkei newspaper, which obtained a memo written by a former head of the Imperial Household Agency that quoted Hirohito as expressing displeasure over the shrine's decision to include Class-A war criminals. The memo itself, which some researchers and journalists were hoping to see, was left out of the record, according to Japanese media reports.

Chris Winkler, a senior research fellow at the German Institute for Japanese Studies in Tokyo, said giving an official imprimatur to Hirohito's remarks would have risked enraging Japan's vocal right-wing.

"They don't want any trouble," he said of the Imperial Household Agency. "They just want the emperor or the imperial institution to stay out of trouble. That's their primary concern."

The record conveys some of the frustrations Hirohito felt early in his reign, through some of the 10,000 "waka" poems he is believed to have written. Only about 900 of the poems are known, including three new ones discovered during the project.

In one, written a few years after ascending the throne in 1926, he lamented that his ideas were not being reflected in palace policies, according to Japanese media reports. Two other poems from 1929 refer to "a missing fruit," an allusion to the frugal life at the palace during the global economic slump.

The history says Hirohito was first notified of the U.S. atomic bombing of the city of Hiroshima nearly 12 hours after the blast on Aug. 6, 1945, according to Japanese media reports.

It says Hirohito judged on the evening of Aug. 8 that it had "become impossible to continue the war" and expressed hope that the war would be concluded "as swiftly as possible," according to the reports. The United States dropped another atomic bomb on the city of Nagasaki the next day, and Hirohito announced Japan's surrender on Aug. 15.

The practice of documenting an emperor's reign follows a Chinese tradition, though in earlier times the records were intended mainly for the imperial household.

The annals of Hirohito's grandfather, the Meiji emperor, didn't start coming out until 1968, more than 50 years after his death. The record of Hirohito's father, the Taisho emperor, was only released in 2002 after the Asahi newspaper filed a public records request, and parts were blacked out, triggering criticism.

Hirohito's official history was completed this year and presented to his son, current emperor Akihito, in August. The 24-year project cost 200 million yen ($1.9 million), not including personnel costs for a staff that averaged about 26 people.

The release of the history was the lead story in Japan's major newspapers Tuesday, playing bigger than tennis star Kei Nishikori's bid for the U.S. Open championship.

The relatively quick release of Hirohito's record, 25 years after his death in 1989, was welcomed as progress by the media and scholars. It's also the first time the annals were written in modern Japanese, instead of a less-accessible archaic form of the language. None of the annals was blacked out, though that left many wondering what was left out.

Hirohito "is a first-rate witness of his era, which is an extremely turbulent part of Japanese history, and historical studies of that era are moving forward beyond views that tend to see the royals as taboo," the Nikkei newspaper said Tuesday. "But we should remember that the record is not a complete documentation of his accounts and try to read the Imperial Household Agency's intentions."