Bansenjukai. The Desktop Ninja Handbook

"Bansen-shukai" is the oldest surviving manual on ninjutsu, compiled in the 17th century by the outstanding ninja Samudzi Fujibayashi. Soon after its publication, the book became the main educational manual for most ninja clans and remained so until the end of the 19th century. This book is still used today to train Japanese special forces fighters. The book describes in detail the philosophy and moral code of the ninja, basic techniques, methods of hand-to-hand combat, rules of concealment, ways of recruiting agents and gathering information, as well as proper methods of attack, preparation of poisons, and organization of assassinations. The book is a treasure trove of specialized knowledge and Eastern wisdom.