According to Document 1 of Section 11 of Chapter 5 in "Nihon Shoki," both Amaterasu Omikami and Tsukiyomi no mikoto were ordered to rule the heavens, but later Tsukiyomi no mikoto was told by Amaterasu Omikami in the world above to meet Ukemochi no kami (the god of grains), so he (or she) visited her.
書紀第五段第十一の一書では、天照大神と月夜見尊がともに天を治めるよう命じられたが、のちに天上で天照から保食神（ウケモチ）と対面するよう命令を受けた月夜見尊が降って保食神のもとに赴く。