Although Amaterasu omikami-the god of the sun-is considered to be the ruler of the firmament as she is depicted in "Kojiki" and "Nihon shoki" as ruling the heavens or Takamagahara, there are conflicting stories about the domain of Tukuyomi-the god of the moon; one in "Nihon shoki" says that Tukuyomi was placed in the heavens next to the sun, and another says that he (or she) was ordered to rule the country of the night or the ebb and flow of the tide.
ツクヨミの管掌についても、『古事記』や『日本書紀』の神話において、日神たるアマテラスは「天」あるいは「高天原」を支配することでほぼ「天上」に統一されているのに対し、月神の支配領域は、『日本書紀』に「日に配べて天上」を支配する話がある一方で、「夜の食国」や「滄海原の潮の八百重」の支配を命じられている話もある。