Kirito and Kazumi are from the hidden clan, the Ryuu clan. The Ryuu clan was hidden from the rest of the shinobi world and were protected by the Genjutsu barrier, for the Ryuu clan had special powers and had to protect the powerful Kirito and Kazumi, for they had the elemental dragons in them. (Kirito gained lightning, fire and a bit of earth, while Kazumi gained wind, water and a bit of earth). The village ninjas also had to protect the secret scrolls in the forbidden chamber of secrets.