Japan's last formal use of shinobi took place in the years before and during the Second World War; and it is only because they existed in recent history, and because their deeds were vile and atrocious, that the Japanese spies of WWII are not yet graced with the appellation "ninja." Their many covert actions are recounted here. The objective of this book is not to glorify or validate their abhorrent actions, but merely to ensure we keep an accurate historical perspective of who we are emulating in our practice of the ninja arts.