Nindo

From Narutopedia

A nindo is a "Ninja Way," a rule for the particular Shinobi to live by. It is their way of ninja life, their motto. It can also be taken as a dream. A ninja's nindo can be anything no matter how immoral their personal point of view is. Most often Naruto Uzumaki proclaims his nindo, his ninja way to be: "I never go back on my word, that is my nindo! My ninja way!"