Ranpou is the current head of an obscure ninja clan who has trained since infancy in his family craft. When he was sixteen, he obtained a powerful scroll and gained the ability to change his shape at any given time. His talents were recognized by the Japanese government (remnants of the shogunate), and he is recognized as a class A agent for them. He wears his ninja suit, Kageie, and was given the codename Fudohmaru. While he was training one day, his foster father passed away and Ranpou was given a new mission from the government. They order him to eradicate Bernard High School due to its recent suspicious activities.