KOSHU, Yamanashi Prefecture--An earthenware bowl engraved with a poem written entirely in hiragana more than 1,000 years ago about the sorrows of parting was unearthed at an archaeological site here.

Researchers said the find offers fresh clues on the spread of the phonetic writing system from Kyoto, which was then the capital of Japan, to local regions.

The clay bowl is almost perfectly preserved. It was unearthed in the ruins of a residence that existed in the Heian Period (794-1185) in the Kekachi archaeological site.

The find was announced Aug. 25 by the city government and board of education.

Minami Hirakawa, head of the Yamanashi Prefectural Museum and an expert on Japanese ancient history who studied artifact, called it “an invaluable first-class discovery.”

Hirakawa noted that the bowl dates from the period close to around 935, when "Tosa Nikki” (Tosa Dairy), a work entirely in hiragana was written by Ki no Tsurayuki, a reputed poet and court nobleman.

“No other poems have been found from that period written entirely in hiragana,” he said. “This makes it extremely important in terms of understanding how hiragana spread from the capital to the countryside.”

According to the announcement, the reddish brown bowl is unglazed and measures 12 centimeters. It was inscribed with 31 hiragana, including one that was presumed to be written on a missing chipped fragment, in five lines.

Experts believe that the characters were written with the tip of a bamboo spatula while the clay was still drying.

The poem, a 31-syllable Japanese style of verse, is original and not mentioned in the “Manyoshu” (Collection of Ten Thousand Leaves), the oldest existing anthology of Japanese “waka” poetry, which was compiled in the eighth century, or other anthologies.

The poem is thought to convey the sorrows of parting as it contains the word “shikeito” (coarse silk yarn), an expression used often in poems about love and parting.

The strokes suggest that the poem was written by a highly cultured individual, perhaps an envoy assigned by the imperial court to a local region, experts said.

They speculated that the bowl was presented as a farewell gift to a local leader at a function given to that person finishing his term in office. The overall impression is that the assembled guest were sophisticated as well.

The origin of hiragana dates to the eighth century.