Seiko Fujita was born Isamu Fujita on February 10, 1898, and died on January 4, 1966. But between those dates lay the strange and shadowy life of a man known as a scholar, an author, and—perhaps—a ninja. Today, debate still rages about whether Seiko Fujita was a true master of the ancient art of ninjutsu or merely a clever fraudster. He became infamous for his grotesque, often bizarre displays: eating glass, carving strips of flesh from his own body, the kind of spectacle that blurred the line between demonstration and self-destruction. At one point, he dabbled as a prophet and fortune teller, a phase he recounts in detail in this very book. He moved among gangsters and gamblers, men who thrived in the underbelly of society. This colorful notoriety only deepened the murky ambiguity that surrounds his legacy. Yet, amid the swirling rumors, two facts stand solid: Fujita trained the elite soldiers of the Imperial Japanese Army at the famed Nakano Academy in the ways of Koga ninjutsu; his peers acknowledged him as a true master of the art. Whatever else one might say about him, those are undeniable truths. In this book, Fujita makes a sincere attempt to adapt the ancient techniques of ninjutsu to the needs of a rapidly modernizing world. In this endeavor, he faced the same trials as other great martial arts masters of his time. If, like me, you believe ninjutsu is steeped in Genjutsu—the art of illusion—then you will see the controversy surrounding his life and work as his final, most masterful trick.