is the earliest extant poetry collection in Japan. Similar to the Book of Songs in China, the poems collected from the 4th century to the mid-8th century are long and short, and there are always different opinions on the date of their completion and the editors, but most of them are works from the Nara period (AD 71-784). It is generally believed that the collection of poems was compiled and passed down by many people for many years, and was completed by ōtomo no Yakamochi (717 ~ 785 AD) in the second half of the 8th century. Later, it was revised and approved by several people before it became the current version.