Ninpo is a collection of techniques for protecting the mind and spirit, in contrast to ninjutsu, which is primarily concerned with the physical realm.

Ninpo was the featured martial art in the horror/fantasy anime, "X". Ninpo has seen references in such films and books along this Japanese vein; one American example being John Allen's "REALM" series, where the main character, Timothy Barnhill, is attuned in the art of metaphysical discipline.