What is "man'yogana"

n. the early Japanese syllabary using Chinese characters to represent Japanese sounds: the predecessor of hiragana and katakana

is an ancient writing system that employs Chinese characters to represent the Japanese language and was the first known kana system to be developed as a means to represent the Japanese language phonetically. The date of the earliest usage of this type of kana is not clear, but it was in use since at least the mid seventh century. The name "man'yōgana" is from the Man'yōshū, a Japanese poetry anthology from the Nara period written in man'yōgana.