Judging from Johyobun (memorial to the Emperor) of the five kings of Wa, an inscription of the mirror of Sumidahachiman-jinja Shrine, and an inscription on an iron sword which was excavated from Inariyama-kofun Tumulus in Saitama Prefecture, et al., it is thought that characters were used in Japan in the fifth century.
倭の五王の上表文や隅田八幡神社鏡銘、埼玉県稲荷山古墳出土鉄剣銘文などから、5世紀代には文字が日本で使用されていると考えられている。