Ashura was the younger of Hagoromo's two sons. He was gifted with Hagoromo's body and physical energy. Things didn't come easy for Ashura and he had to work harder for what he wanted, but through his efforts he learned to connect with others and that people needed to work together to achieve things. Hagoromo, when deciding upon a successor before his death, was impressed with Ashura and chose him to lead. When Indra attacked Ashura out of jealousy, the two brothers perished in battle.
He was reincarnated numerous times over the millenium, his most recent reincarnations being Hashirama and then Naruto.