Tensho (literally the 'Book of Heaven', also called Amatsufumi or Amenofumi) is a chronological history that is said to have been compiled by FUJIWARA no Hamanari at the end of the Nara period. It is also known as Tenshoki (written as 天書記 or 天書紀) and Hamanari Tenshoki. Ten volumes in total. Although there is no way to verify the theory that it was compiled by FUJIWARA no Hamanari, there is no evidence that Hamanari was ever promoted to Dainagon (Major Councilor). For this reason, it should not be accepted blindly. It is one of the Koshi Koden (ancient history and legends excluded from official histories).
The "Tensho" exists in three different versions.
The "Tensho" as surviving fragments (original does not exists except for surviving fragments)
Its surviving fragments are quoted in the following manuscripts: one article in the "Chokan Kanmon" (Prayer of the Chokan Era), twenty-eight articles in the "Shaku Nihongi" (Annotated Nihonshoki [Chronicles of Japan]), and others in the "Shosha kongenki" (literally, the records of historical origins of shrines) and the "Nihon Shoki Sanso" (Interpretations of the Nihonshoki [Chronicles of Japan]).
The "Tensho" (complete)
Ten volumes in total (a history written in chronological order from the Age of the Gods to the reign of the Empress Kogyoku)
While it is considered to be the same work as the first version above since it roughly includes the surviving fragments, there is another theory that it is a forgery of the early-modern period based on the surviving fragments. No conclusion has been reached yet on the differences between the surviving fragments of the Tensho and this complete version.
"Tenshoki" (abridged version)
Ten volumes in total (only stories from the Age of the Gods)
The contents are different from those of the surviving fragments.
In addition, it is likely to be a forgery by later generations because the "Honcho shojaku mokuroku" (Catalogue of Books in Japan, the oldest known work of its type) describes it as 'Tensho, in ten volumes' and 'compiled by Dainagon FUJIWARA no Hamanari.'