Board Thread:Theories and Speculation/@comment-28832247-20160624022502/@comment-1251315-20160705231129

Derpyrebound wrote: We will never know for sure until Kishimoto gives us more backstory for him. I mean, we get plenty for majority of the others like Sasori and Nagato. And that's not going to happen because Kishimoto has no further involvement in the Naruto series. He ended the series with Chapter 700 and Gaiden.