Yoshimori and Tokine are just your average kids who go to the same school and they also happen to be neighbors. During the day they go their separate ways but at night they both have to go protect the land of Karosumari, which is also where their school is. This obligation has been passed down to both of them, as both of their families come from a long line of Kekkaishi, protectors who excise spirits/demons that try to gain power from the high amounts of spirit energy exuding from Karosumari. Their families may be "rivals" but the two of them get along just fine. At night, Yoshimori and Tokine, with their demon dogs Hakubi and Madarao, do their best to rid the land of evil, but everything isn't always so simple.