Hi joesixpack
Sorry I didn't respond earlier, I missed seeing your post.
It's based on Bills own study of the kata Gojushiho, and how he adapts this one kata as a complete fighting system against HOV (Habitual Acts of Violence)
Bills base style is shotokan, but this is not a shotokan book.
Again, I highly recommend it.
If you want to discuss further, drop me an e-mail.
Regards
JohnL