Board Thread:Naruto Discussions/@comment-29752445-20160826022014/@comment-4912646-20160826222011

To answer this, you need to understand that we've essentially been given three different versions of events that don't quite fit together:
 * The first version, given from the Sage of Six Paths' introduction until his actual debut in chapter 670, says Hagoromo alone sealed the Ten-Tails inside himself, then later created the tailed beasts as his life neared an end to prevent the beast from reviving, then finally created the moon in order to seal away its husk.
 * The second version, given from chapter 670 until the end of the manga (and in the databook), says Hagoromo and Hamura together sealed the beast in the moon, then Hagoromo later divided its chakra into the tailed beasts because he was inspired by how Asura lived his life. Hagoromo still says the Ten-Tails was inside him, meaning the brothers likely sealed its chakra within him and its body inside the moon, though this was never actually explained anywhere.
 * The third version is given in the anime's recent filler episodes and it is a mess of contradictions, not only with earlier episodes/chapters but also with itself. According to this version, Kaguya and the Ten-Tails were two separate entities, Hagoromo knew that Kaguya was Ten-Tails along, Kaguya was the one sealed in the moon (meaning she became the Demonic Statue), Hagoromo created the tailed beasts way before Asura was born, he never actually became the Ten-Tails' jinchūriki, and so on. To top it off, the episode after we see Kaguya get sealed in the moon, Hagoromo claims Ten-Tails was also sealed along with her, which as we clearly saw didn't happen.

Narutoka5 wrote: where in the anime and manga did hagoromo say he split the jubi based on Ashura's life? in the filer episodes in the anime they show hagoromo split the jubi right after they seal it, before ashura was even born, and besdes those fillers I don't remember him ever saying he was inspired by ashura. He says this in chapter 670 and episode 420. As for Hamura, going by the databook he left soon after the moon was created, before Indra and Asura were born. Hagoromo creating the moon at the end of his life was from the wrong version of events given by Obito, it was actually created when the brothers defeated the Ten-Tails according to Black Zetsu.

If you want to know the full manga version of events from before the anime started messing with it, you can read a translation of them here.