These videos cover Kosho no Kenza - the second part in the Strategies texts. (Book not Included)
Kosho no Kenza deals with the subconscious elements of martial arts. The concepts are based on trickery and subtle manipulation of the opponents perception. These concepts are very abstract, yet they are exact. To study this, you must be prepared to operate on pure principle of feeling and understanding of one's space, time and self.