Board Thread:Theories and Speculation/@comment-25086462-20150705235225/@comment-5936871-20150706031614

The databook stated that Hamura departed to the Moon with the rest of the clan and all of his descendants. He also used his god-like power to permanently seal away the Byakugan of all of his descendants so that when born their eyes would become apart of the Tenseigan Energy Vessel to power it and they were all born blind. Therefore, the Hyuga and Kaguya cannot come from Hamura but from Hagoromo. The Hyuga's Byakugan just has high biocompatibility with Hamura's Otsutsuki descendants cause they all use to have it. So once Toneri obtained a Byakugan from his cousin clan, he obtained a power that was sealed away for centuries within his clan and therefore awakened the Tenseigan due to the accumulation of so many years of sealed power manifested in his eyes.

I'm going to assume the Hyuga and Kaguya both come from Indra like the Uchiha do, since the Hyuga's origins lie with the Uchiha's, and the Kaguya seem to be more related to Indra than they do to Asura due to appearance, personality, ect.