Shinobu is a Ninja Private School student who dreams of becoming a professional Ninja. She tries to fulfill the assignments given to her by her boss, Touryou, together with her insane assistant, Onsokumaru. Everyday is a challenge, and to fulfill her assignments, she comes to the normal Japanese world and encounters Kaede. In spite of Shinobu’s incompatible requests, Kaede and Shinobu establish a stable friendship. But their friendship will be put to the test as the assignments escalate and as Kaede starts to realize the truth about Onsokumaru.