At last, the secret of manufacturing Ninja smoke producing devices is revealed. In this book, Toshitora Yamashiro, grandmaster of the Nine Shadows of the Koga Ryu (author of Deadly Weapons of the Koga Ninja), explains in explicit detail the fine art of Yogen (Ninja Chemistry). Learn the simple procedures for making smoke devices from readily available supplies. Sections on strategy and techniques tell how to evade the enemy, vanish into an exploding smoke cloud and create distractions. This manual is step by step, fully illustrated with many secrets never before printed and provides one more skill of the legendary Koga Ninja.