Board Thread:Naruto Discussions/@comment-36006024-20180926134241/@comment-26107879-20181002045325

Anyone even without Hagoromo had the components to create Chakra. All Chakra is, is the mixture of Physical and Spirtual energy. The problem is they didn't have the ability to connect their energies cause you need Chakra to connect the energies. So you need Chakra to create Chakra. The tree produced a fruit composed of Chakra. Kaguya ate it and got Chakra. She passed it on to her sons. Hagoromo then used his Chakra to connect people's spiritual and physical energies.