As Black Zetsu drains Naruto and Sasuke's Chakra into the reborn Kaguya, Black Zetsu tells the story of Kaguya's children: Hagoromo and Hamura in a world ruled by the Infinite Tsukuyomi. Filler episode.
Near the Divine Tree is an area known as the Peak of Demise. No one is allowed to go near it, except those chosen by Kaguya to undergo a ritual she has established. Gamamaru, a Sage Toad, says the truth lies beyond the peak-those words stir Hagoromo's curiosity, and he decides to head out to investigate.—TheTVDB