Board Thread:Episode Discussions/@comment-1181222-20170809100834/@comment-734582-20170811185455

Crazylazyguy wrote: The book seems relatively new, I'd say that it was indeed Sasuke. After all, he was there when Tobirama explained everything about the Sharingan. It's probably a collection of new information, including declassified stuff like Tobirama's research. I don't see when Sasuke could've written it.