Board Thread:Naruto Discussions/@comment-25442710-20140920121351/@comment-26302001-20141001193539

You are forgetting that Hashirama gave Sasuke his chakra. Then after that Kabuto used Hashirama's DNA to repair Sasuke's heart. He does have Asura Chakra in him. I don't understand why he didn't awaken the normal Rinnegan in both eyes though like Madara...

Also.. Hashirama obviously did not have Dojutsu, yet Black Zetsu was trying to get him to awaken the Rinnegan too as Black Zetsu said himself. So in short you don't need a Dojutsu from the start.. you would just awaken it as if you were an Uchiha awakening the Sharingan for the first time.