Amano began training to be a ninja at a young age, and many years before “returning to the faith” (chozer b’tshuvah), as Jews refer to the process of becoming Orthodox. Like many kids, Amano wanted to be like the ninjas he saw in movies. So at nine years old he started to train in karate. Three years later, he happened upon a notice for a small ninjutsu group.
He immediately began to train with Shai Goshen, a pupil of Yaakov Hazan who was a student of Doron Navon, the first Western Jew to study under Masaaki Hatsumi, the 34th and current ninjutsu grandmaster. It...