|A book of secrets that details a variety of techniques for use with Shinobi Prosthetics. Grants the ability to learn "Prosthetic Style" skils.
Written by a man who abandoned the path of the Shinobi, but could not bring himself to discard his painstaking research.
- Given by the Sculptor after fitting the Prosthetic Arm with at least three Prosthetic Tools.
- Found next to the Workshop in the Dilapidated Temple, if not given by the Sculptor prior to the final invasion of Ashina Castle and Outskirts by the Central Forces.
The earliest this item can be unlocked is after retrieving the Shuriken Wheel, Robert's Firecrackers from Ashina Outskirts and either the Flame Barrel from Hirata Estate or Gyoubu's Broken Horn from Ashina Castle.