The myth of the ninja is based not only on their superior combat skills but also on the fact that they were masters of camouflage and concealment. This aspect of ninjutsu is often overlooked or only briefly touched upon in many books or training courses today. Therefore, the well-known authors Ashida Kim and Andreas Leffler have dedicated this book entirely to the themes of invisibility and stealth. These areas are distinct art forms and remain essential components of training for numerous special units even today. It is clear that they can be more than just a supplement to combat training; they represent their own unique art forms. A comprehensive education in these areas would naturally exceed any self-defense course or publication, but this book may still appear interesting to the curious ninjutsu student.