Board Thread:Theories and Speculation/@comment-3568954-20150523051244/@comment-25093611-20150526165245

i actually thought thhat the reason was because naruto and minato didnt have kuramas full body, each had only a piece of the kyuubi which allowed them to create a chakra-kyuubi-body (or: made them unable to transform into the full kyuubi),

and after naruto got both halfs he can still use it because we have no evidence that yin and yang kurama fused again, maybe they cant <_< ^_^