Karasumori School has a 14-year-old student named Yoshimori Sumimura who belongs to the Sumimura clan, a family of Kekkaishi that has been practicing magical barrier arts for 22 generations. Despite his heritage, Yoshimori finds himself embroiled in a fierce competition with his childhood friend and fellow Kekkaishi, Tokine Yukimura, as they both strive to become the rightful heir to the clan's mystic arts. Nevertheless, Yoshimori remains resolutely committed to honing his skills and safeguarding people from malevolent forces, even in the face of daunting nightly challenges.