The Nabari no Ou anime and manga series features an extensive cast of characters created by Yuhki Kamatani. The series takes place in a modern-day Japan where the ninja world of Nabari (隠の世, lit. World of Concealment) is hidden from the surface world, a name given to the world unaware of Nabari. The series' storyline follows Miharu Rokujou, a 14-year-old student who unknowingly possesses a powerful secret art within him, and his introduction into Nabari upon his power's activation.
The protagonist of the series Miharu Rokujou remembers nothing of his childhood and lost his parents at an early age. However, he is not concerned by this and strives to live a normal life. This plan is compromised when Miharu is attacked by real ninja and Koichi Aizawa and Tobari Kumohira come to his aid. There, Miharu learns about the hidden ninja world of Nabari and the Shinra Banshou, a powerful secret art containing all of the world's knowledge, which resides inside of him. This secret art is so powerful, the possessor is revered as the King of Nabari and is sorely coveted after. To protect himself, Miharu is forced to join his school's Nindō club managed by his two protectors. Kumohira vows to find a way to remove the secret art from Miharu. Until then, Kumohira, Aizawa, and Raimei Shimizu, a samurai from their ally the Fuuma Village, must protect Miharu from the Grey Wolves, a squad of elite ninja who lead the search for the secret art, and foil the Grey Wolves' attempts to gather each ninja village's kinjutsushō (禁術は, lit. Forbidden Technique).