Board Thread:Theories and Speculation/@comment-1512913-20150131165206/@comment-25343176-20150329111142

Elveonora wrote: We don't know the exact relationship of Kaguya Clan to the Ootsutsuki, that's why I didn't include them. Their bone bodies originated from Kaguya. It is unknown who out of the two brothers inherited the bone body. Thats a big mystery.