This is part of the Ninja Search! Great Research! This proves that the “Straight Blade” Katana, does date before the NINJA BOOK IN THE U.S.A (1980’s) and the NINJA BOOM IN JAPAN (1960’s).
This is pictures and writings about the ashigaru actially using them in the time of the Sengoku Period, and again many know that the Shinobi were primarily out of the Ashigaru class! Great video, I hope that you all enjoy it!