I really appreciate your detailed recounting of Amaterasu’s primary myth. Campbell believes her story pre-dates the Bronze Age. Here are some of his thoughts on the subject, excerpted from an interview with Cate Miodini from 1986 in Anima: An Experiential Journal:
The earlier tradition, so far as my findings go, is the one where the sun is feminine and the moon masculine. The moon is the image of the sacrifice that dies and is resurrected. The moon dies in the light of the sun, and is again born from the light of the sun. And so the sun is the mother of the moon.
That makes the sun feminine. The fire of the sun and the fire of the womb that converts seed into life are equivalent. Also the fire on the sacrificial altar consumes the victim. These are all associated with a mythic consciousness that dates at least from the early bronze age. Here there is a deep sense of the melancholy and tragic quality in life, since the moon, the symbol of life’s death and resurrection, carries its own shadow within itself, as we all do.
You can see something of the influence of myth on language when you consider the Indo-European family of languages. Here nouns have genders, but it’s strange how these change. In German they have a masculine moon and a feminine sun: der Mond, die Sonne. This accords with a myth that extends all the way from the River Rhine to the China Sea, where in Japan the goddess Amaterasu is the sun, her brother being the moon god. Then there’s a myth about the moon brother and sun sister that is known to practically all the circumpolar peoples of the North.