Chapter 5 of "Jindaiki (Records of the Period of Gods)" in "Nihon Shoki" gives a short description of Tsukuyomi, stating that Izanagi gave birth to the god of the brilliant moon next to the sun and sent him (or her) to the heavens to work with the sun as a ruling god, while in Document 1 of Section 1 that follows, Izanagi no mikoto is said to have given birth to Ohirume no mikoto by holding a masokagami (bronze mirror) in her left hand and Tsukuyomi no mikoto by holding the same mirror in her right hand.
『日本書紀』神代紀の第五段では、本文で「日の光に次ぐ輝きを放つ月の神を生み、天に送って日とならんで支配すべき存在とした」と簡潔に記されているのみであるが、続く第一の一書にある異伝には、伊弉諾尊が左の手に白銅鏡を取り持って大日孁尊を生み、右の手に白銅鏡を取り持って月弓尊を生んだとされる。