Board Thread:Theories and Speculation/@comment-25139119-20150820032806/@comment-23887466-20150911220725

Or simply, that scene where Kaguya remembered her sons trying to seal her with Six Paths Chibaku Tensei, is just that they tried to seal her with it but they didn't succeed. She just happened to remember that she once again lost to humans, even though she is the progenitor of chakra.

As for Kurama, he (?) simply didn't know anything regarding Kaguya. According to him (?), the Ten-Tails is the progenitor of Chakra, this came probably from Hagoromo himself as he believe that the Divine Tree came to regain the stolen Chakra, so in his opinion the Tree itself is the progenitor, not his mother.