By night, junior high student Yoshimori Sumimura is a "kekkaishi" - a demon-hunter who specializes in creating magical barriers around his prey. By day, Yoshimori's got some other demons to battle: an addiction to sweets and a seriously crotchety grandfather! Yoshimori's pretty 16-year-old neighbour and childhood friend, Tokine Yukimura, is also a kekkaishi, but their families are feuding over who is the true practitioner of the art.

The governing body of kekkaishi, the secretive shadow organization, sends a young tough named Gen to help patrol Karasumori and protect it from the increasing numbers of ayakashi spirits. But Yoshimori isn't about to sit down and let this punk move in on his territory. It's a kekkai super showdown! Who has the stronger barrier magic?