There are two worlds which exist side by side – the ordinary surface world of the humans and the secret world of ninjas called Nabari. Within this secret world, the opposing ninja groups are fighting over who should possess the ultimate power known as Shinra Banshou. Enter Miharu Rokujou, a high-school student who lives a carefree life and likes to keep himself to himself. Unfortunately for Miharu, his carefree life is about to be over, because within him is hidden the ultimate power and there is no end of evil minions ready to kidnap him for it! Miharu’s only chance of survival is to embrace this mystic world and become the King of Nabari himself. With the help of his new ninja friends, Kouichi, Shimizu, and Kumohira, can he come to grips with his powers or will he fall prey to his many enemies instead?