Drafts of poems that Emperor Hirohito wrote in his late life have been found, with experts saying they are valuable historical materials suggesting his feelings about World War II as well as his postwar role as the symbol of the state.

The drafts of around 250 "waka" poems, about 200 of which were previously unknown, have been obtained by the Asahi Shimbun from an unidentified person who was close to the Japanese emperor, posthumously known as Emperor Showa and father of Emperor Akihito. The newspaper released part of the drafts to other media outlets Tuesday.

The 57 pages of drafts with what experts believe to be Emperor Hirohito's signature contain 31-syllable poems written between 1985 and 1988 about such subjects as the war and his trips to regional areas in Japan, according to the Asahi. The emperor died in January 1989.

In a poem written when he marked the 60th year of his reign in 1986, the emperor expressed his joy at being celebrated by the public. But he also noted he was feeling "ashamed" as he looked back on his past.

Isao Tokoro, professor emeritus at Kyoto Sangyo University, said the poem suggests the emperor's "humility" in reflecting on whether he had performed his role as state symbol sufficiently.

The emperor had confided that he had felt anguish at talk of his war responsibility, according to the diary of one of his close aides, the late chamberlain Shinobu Kobayashi.

Historian Kazutoshi Hando said he believes the emperor "may have regretted his past and expressed his feelings by using the word 'ashamed' (in the poem)."

Another poem he wrote after attending a memorial service for the war dead in 1988 described the emperor offering prayers while thinking back on "the sad war."