Most scholars in Japanese studies (history, linguistics, literature) tend to accept in one form or another the ancient legend that the phonetic writing system of ancient Japan, known as man'yōgana, came from Paekche. This legend about the ancient Korean kingdom—Paekche—appears in the Kojiki and Nihon shoki, Japan's two oldest chronicles. To date there have been few attempts to use concrete data from the peninsula either to prove or reject this legend. This article supplies information from all epigraphic data on the Korean peninsula to show that Paekche spread the use of Chinese (sinographs) to be used phonogrammatically and that Koguryo educated the rest of the peninsula in the use of this script.