In Japanese mythology, the Tenchi-kaibyaku (天地開闢; Literally "Creation of Heaven & Earth") is the story that describes the legendary birth of the celestial and creative world, the birth of the first gods, and the birth of the Japanese archipelago.
This story is described at the beginning of the Kojiki, the first book written in Japan (712), and in the Nihon Shoki (720). Both form the literary basis of Japanese mythology and Shinto; however, the story differs in some aspects between these works.
In Shinto, Kotoamatsukami (別天津神; literally "distinguishing heavenly kami") is the collective name for the first gods which came into existence at the time of the creation of the universe. They were born in Takamagahara, the world of Heaven at the time of the creation. Unlike the later gods, these deities were born without any procreation.
The Nihon Shoki (日本書紀) or Nihongi (日本紀), sometimes translated as The Chronicles of Japan, is the second-oldest book of classical Japanese history. It is more elaborate and detailed than the Kojiki, the oldest, and has proven to be an important tool for historians and archaeologists as it includes the most complete extant historical record of ancient Japan. The Nihon Shoki was finished in 720 under the editorial supervision of Prince Toneri with the assistance of Ō no Yasumaro and presented to Empress Genshō. The book is also a reflection of Chinese influence on Japanese civilization. In Japan, the Sinicized court wanted written history that could be compared with the annals of the Chinese.
The Nihon Shoki begins with the Japanese creation myth, explaining the origin of the world and the first seven generations of divine beings (starting with Kuninotokotachi), and goes on with a number of myths as does the Kojiki, but continues its account through to events of the 8th century. It is believed to record accurately the latter reigns of Emperor Tenji, Emperor Tenmu, and Empress Jitō. The Nihon Shoki focuses on the merits of the virtuous rulers as well as the errors of the bad rulers. It describes episodes from mythological eras and diplomatic contacts with other countries. The Nihon Shoki was written in classical Chinese, as was common for official documents at that time. The Kojiki, on the other hand, is written in a combination of Chinese and phonetic transcription of Japanese (primarily for names and songs). The Nihon Shoki also contains numerous transliteration notes telling the reader how words were pronounced in Japanese. Collectively, the stories in this book and the Kojiki are referred to as the Kiki stories.
In Japanese mythology, the Kamiyo-nanayo (神世七代; lit. "Seven Generations of the Age of the Gods") are the seven generations of kami that emerged after the formation of heaven and earth(Tenchi-kaibyaku).
According to the Kojiki, these deities appeared after the Kotoamatsukami, which appeared at the time of the creation of the universe. The first two generations were hitorigami while the five that followed came into being as male-female pairs of kami: male deities and sisters that were at the same time married couples. In total the Kamiyonanayo consist of 12 deities in this chronicle.