Ninpo is another word for Ninjutsu-The martial arts of Ninja (or Shinobi and not well known Kancho). Ninpo represents the larger scale of ninjutsu-The spiritual aspects (including Amatsu Tatara, spiritual refinement ect) and the Physical aspects (Taijutsu, Bikenjutsu, Sojutsu, Naginatajutsu ect). Collectively they are called Bumon and Shumon, and make up Ninpo. Ninpo translated as *Ninja law* would be incorrect, Ninpo actually translates as *Higher order of Nin*, *Higher order of Ninja* or *The way of Nin/Ninja* ect. The Nin simboll consists of uper radical and lower radical's, upper being Yaiba being a sword, lower being Kokoro/Shin being heart. A misconceptional translation of the word Nin would to put the blade over the heart which sounds sinister, but actually it represents preservance and endurance. Po consists of two radicals, the left radical being Sansui meaning water and Saru meaning to go fourth. Putting them together literally means water going forth but on a deeper scale implies the water cycle, and when Po is used in Ninpo, relates to the term Do used in many arts meaning The Way.
Ninpo is the higher order of Ninjutsu, representing Bumon and Shumon, The left and right hand, representing Yin and Yang.