Board Thread:Versus Debates/@comment-26005711-20150512133037/@comment-2013124-20150721133156

I don't think the Databooks should be disregarded, they're canon material provided by the original author afterall. I do think we should treat them as if they are from the point of view of non-omniscient characters though and might be flawed as a result.

I would like to point out that Hiruzen was valid in all his fights as a handicapped old man. We never saw him fight at age 30 or 40. Characters who knew him then called him "Miserable" in his old age. One of these was Enma who likely was around to see Tobirama as well. He's the one character with enough perspective to trust, having lived it and not being central to the conflict. And he wasn't scared of the First or Second or Orochimaru, because he knew they could take them all, or at least what he and Hiruzen could do at their best.

Several people have mentioned the FTG being a thing in favor Tobirama. But I'm willing to bet that Hiruzen knew it as well. Hiruzen was famous for his usage of the Shadow Clone Jutsu which is another of Tobirama's classics, and Tobirama was one of his teachers. Plus it provides a chain of custody for the FTG that gets it to Minato, who couldn't have learn it from Tobirama.

After all we know Minato knew before he was Hokage that he was the heir apparent for that job. We also know he had the FTG before he became Hokage. So when did he learn it? The most logical thing, in my mind is right after he rescued Kushina. He demonstrated his "Will of Fire" and rescued the destined jinchūriki of Kurama. He becomes a natural choice at that point. Then he either gains access to the Scroll of Secrets which Hiruzen as Hokage would have had access to or he gets private lessons from the Professor. Likely both.