Jindai moji or Kamiyo moji (Japanese: 神代文字 "characters of the Age of the Gods") are characters said to have been used in ancient Japan. Some have claimed since the mid-Edo period that such ancient characters, for example such as Chikushi characters and Hokkaido characters, have been found in archeological remains, in Kofun and on mountains, but all jindai moji are generally considered to be forgeries. No earthenware with such characters has ever been found.
The concept of jindai moji was first addressed at the end of the Kamakura period. Urabe no Kanekata (卜部兼方) mentioned in Shaku Nihongi (1301 or earlier) that his father, Urabe no Kanefumi, argued that the ancient Japanese could not have performed bone-style fortunetelling with turtleshells (亀卜, Kameura, "turtle fortunetelling"), as described in the Nihon Shoki, without having a writing system. The Urabe (卜部) had a family monopoly on plastromancy (卜 : uranai divination using deer scapula or turtle plastrons), giving them a family interest in claiming perpetual service to the Imperial family even before the arrival of Chinese culture. (The modern view is that plastromancy was part of Chinese culture, and entered Japan in company with the Chinese writing system; the only candidate for the clan that brought this from China to Japan is the Urabe clan itself.)
Some examples of jindai moji appeared during the Edo period, each set being named after its supposed source. Even then, the authenticity of jindai moji was supported by scholars such as Tsurumine Shigenobu (鶴峯戊申), and at least one scholar, Hirata Atsutane, changed his opinion from negative to positive. Other scholars, such as Kaibara Ekken, Dazai Shundai (太宰春台), Kamo no Mabuchi, Motoori Norinaga and Tō Teikan (藤貞幹), rejected both the concepts and the claimed examples. The most famous publication denying the existence of jindai moji was Jindaiji ben (神代字弁), attached to Kana no motosue (仮字本末) by Ban Nobutomo (伴信友), which appeared in 1850. The skepticism about jindai moji that developed in the Edo period has been the prevailing attitude among scholars ever since.
In 1930, a religious sect, Kōso Kōtai Jingū Amatsukyō, was charged with lèse-majesté by the special higher police. Amatsukyō was based around documents that were partly written in what its members said were jindai moji. Experts in linguistics and other scholars gave evidence in court that the documents were forgeries. The documents and other artifacts of this sect were destroyed in the American bombardment of Tokyo during World War II.
Some recent writers[who?] have interpreted the following passage in the Shaku Nihongi to support their view that jindai moji were in use in ancient Japan: "There are six or seven documents written in characters of Hi Province (肥人の字、Ahiru characters) in the Ministry of the Treasury."
It was reported in the late 19th century that ancient characters had been found in Ryukyu and in Ezo. These claims received some support from mainstream scholars at the time.
伴信友著。嘉永3 (1850) 年門弟が刊行。