Board Thread:Naruto: The Last Discussion/@comment-5407586-20141206093403/@comment-945885-20141207000131

Archangel489 wrote: why is the book treating it like the moon was created and hamura departed and hagoromo was still alive to spread nishu It's slightly different from some of the original explanations and perhaps a minor retcon of Kurama's one bit of dialogue about it, but that's what happened.

Hagoromo and Hamura fought and sealed Ten Tails using Six Paths Chibaku Tensei, with Hagoromo presumably taking its chakra, since the Gedo Statue is what was sealed in the moon. Hamura and the clan departed for the moon to watch over the Gedo Statue and observe mankind so that they could pass judgment on them after a thousand years. Hagoromo stayed behind to spread ninshu, hoping to bring peace and order to the world. When he was nearing death, he partitioned Ten Tails' chakra to create the nine biju, then died some time later (he didn't die immediately because he was still synchronized with the Gedo Statue).

At least, that's roughly how it went. There are still some contradictions in some of the tellings that can't be reconciled... but, of course, not all of the tellings were told by reliable sources, either, which excuses some of the inconsistencies.