User blog comment:FortressSwan/Confusion & What I Believe to be Contradictions/@comment-26461986-20130215163457/@comment-4347663-20130215163801

It isn't stated as to how they obtained. The only one who has a reasonable explanation as to how they obtained the Wood Release was Yamamoto. Where did all of this come from? Hashirama - whom is the only one who really possesses the Wood Release.