Undated, a collection of manuscript documents from different times periods, described as being Ninja Ninjutsu Densho (Instruction manual) of Iga Koka Ninjutsu. . Of course I have no comments on accuracy of the claims. That said, they went for a very considerable price.
Winning bid: 722,700¥ ($7,913 USD)

You can view pictures of the documents via this link: https://page.auctions.yahoo.co.jp/jp/auction/w1079541023

#JapaneseManuscripts #Ninja