Apathetic middle-schooler Miharu Rokujou is unfazed by the revelation that his body contains the nabari (or, hidden) world's most powerful and secret art, the Shinra Banshou. So when various ninja and other clans' representatives start trying to protect / control / kill him, he's not overly concerned, much to the frustration of those trying to convince him they have his best interests at heart. He does eventually settle for hanging out with the local Banten Village outfit, but largely because keeping their company offers the path of least resistance, since the familiar face of his kind teacher, Kumohira-sensei, is among them. But when a quiet, expressionless young assassin from a different group, the Grey Wolves, secretly asks for his help independent of any clan, Miharu finds his habitual apathy shaken. Yoite is dying. His use of the nabari world's deadliest and most forbidden art, Kira, is quickly killing him. Tired of knowing only emptiness and pain, Yoite wants Miharu to use the Shinra Banshou to erase his existence. Miharu, sensing a kindred spirit, agrees to help. But Kumohira-sensei, closely guarding his own painful secrets, is dead-set against the Shinra Banshou's use and vows to stop Miharu if he tries to invoke it--just as he has sincerely vowed to defend the boy with his life.
Meanwhile, Raimei Shimizu, one of Miharu's new friends and heir to a once-great samurai clan, is on the trail of her prodigal brother, Raikou, whom she believes murdered their family and destroyed their clan years ago. But when she finally confronts him, will she be able to hear the truth he refuses to utter?
This is an emotionally involving series where the politics and mysticism confuse but the personal struggles of the protagonists draw you in and make you care, anyway. The distinctive art's thin, fragile figures add to that attachment and make you worry all the more for the characters. Frail, resigned Yoite makes me want to cry, and watching Miharu slowly emerge from his own self-imposed numbness to help him is bittersweet.