Jindai moji or Kamiyo moji (Japanese: 神代文字 “scripts of the age of the gods”) are characters said to be scripts used in ancient Japan. By debates since the Edo period and Japanese academic society, Jindai moji is considered forgery. Although ancient character researchers insisted their existence, as Uetsufumi or Hotsumatae found, it is denied in historiography due to no existence of earthenware with it. Those believing in the existence use the word Jindai moji to mean "ancient characters". Since about the mid-Edo period some have claimed ancient characters were found in remains, Kofun and mountains such as Chikushi characters, Hokkaido characters. Hundreds of Jindai moji were said to be found.
Jindai moji was first addressed in the end of the Kamakura period by Urabe no Kanekata (卜部兼方) in Shaku Nihongi, mentioning his father Urabe no Kanefumi, who assumed ancient people could not have performed bone-style fortunetelling with turtles (亀卜, Kameura; turtle fortunetelling) as described in Nihon Shoki without characters. Though there were no Jindai moji characters introduced in the Muromachi period, some types of Jindai moji appeared in the Edo period, each named after the source article or place of discovery. Skepticism over their existence erupted in the Edo period. Japanese academic society denies their existence. In 1930, the religious group Amatsukyō was charged with Lese-majesty by special higher police. Amatsukyō used documents that was partly written in Jindai moji (introduc Koshikoden into as the Scripture) and some famous scholars or educators in linguistics had to give testimony in court to prove how the documents in Jindai moji were forgeries. Since positive opinions on Jindai moji sound occultist to Japanese people. Jindai moji is completely denied in the literature.
In the Edo period, existence of Jindai moji was disputed, but supported by scholars such as Tsurumine Shigenobu (鶴峯戊申). Hirata Atsutane changed his opinion from negative to positive. Some scholars denied the existence of Jindai moji such as Kaibara Ekken, Dazai Shundai (太宰春台), Kamo no Mabuchi, Motoori Norinaga and Tō Teikan (藤貞幹). The most famous article 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), empirically denying their existence and concluding them to be forgeries.
Summary of arguments against:
- Ancient document
- Number of syllables and writing method of Kana mismatched with Old Japanese
- Shinkichi Hashimoto studied documents in the Nara period written in Man'yōgana and found Jōdai Tokushu Kanazukai which proved there were 88 syllables. However, the syllables in most of Jindai mojis matched Gojūon and Iroha which were formed in the Heian period. Also, Jindai moji does not follow Old Japanese Kana order.
- No existence before the Heian period
- There must have been no need to use Man'yōgana and invent Hiragana and Katakana if they already had unique characters.
Jindai moji are rejected by the Japanese academic community based on the general lack of evidence. Recent archaeology has failed to produce any evidence to indicate ancient usage of Jindai moji.
While scholars generally have negative opinions, some such as Inbe Masamichi (忌部正通)、Arai Hakuseki、Hirata Atsutane 、Takamasa Omiya(大国隆正) affirmed the existence of Jindai moji which Urabe no Kanekata (卜部兼方) first mentioned in Shaku-Nihongi in Kamakura era.
Summary of arguments for:
- Ancient document
- Discovery in recent years
- The number of syllables and writing method of Kana matches Old Japanese 
- The theory that the five old Japanese vowels did not change appeared at Showa Era.Man'yōgana use Chinese characters, so unnecessary differences of writing were carried out in Jōdai Tokushu Kanazukai since Japanese introduced a logographic system (analogous to the introduction of Phoenician into Greek).
The usage of Jindai Moji
||This section possibly contains original research. (November 2011)|
Representative uses are as follows.
- Shinto. E.g., Shintai of Jinja, Amulet, Ofuda, and so on.
- Dedication for Jinja. (Jingū Library of Ise Grand Shrine has many documents)
- A kind of code of Ninja.
- To prevent forgery of currency
Famous Jindai Moji
- Woshite characters（ヲシテ文字）
- Izumo characters（出雲文字）
- Ahiru characters（阿比留文字、肥人書）
- Ahiru kusa characters（阿比留草文字、薩人書）
- Tsukushi characters（筑紫文字）
- Katakamuna characters（カタカムナ文字、八鏡化美津文字）
- Hokkaido characters（北海道異体文字、アイヌ文字）
- Ryukyu characters（琉球古字）
- Toyokuni characters（豊国文字、神宮文字）
- Tsushima characters （対馬文字）
- 『上古文字論批判』 新村 出 (1898) Shinmura Izuru Criticism on ancient character theories
- 『國語学概論』 橋本進吉  (1925) Shinkichi Hashimoto Introduction of national language study
- 『藝林』(藝林會発行)第4巻(1958) ("Geirin" vol.4 Geirinkan)
- 『日本古代文字考』 落合直澄(1888) Naozumi Ochiai Thought on Japanese ancient characters
- 『神代文字研究原典』吾郷清彦(1975)Kiyohiko Ago The original of Study of Japanese ancient characters
- Tsukishima, Hiroshi (1964). Kokugo-gaku 国語学 (in Japanese). Japan: Tokyo University Publishing. pp. 47–48.
- Kawaguchi(川口）, Kōfū（高風） (1994). Debate over Jindai moji with Tainin-Risshi [諦忍律師の神代文字論をめぐる論争]. JP: Aichi Gakuin University Journal volume41-3. p. 214.
- Naozumi Ochiai Thoughts on Japanese ancient characters [日本古代文字考] Komakisha 1888; republished by Yahata Shoten 1982
- 神谷由道（1886）『東京人類学会報告』第9号 Yoshimichi Kamiya（1886）Anthropological Science（Japanese Series） No.9
- 坪井正五郎（1887）『東京人類学会雑誌』第18号 Shogoro Tsuboi(1887) Anthropological Science（Japanese Series）No.18