Kekkaishi (結界師, "Barrier Master") is a Japanese manga series written and illustrated by Yellow Tanabe.

The series is about Yoshimori Sumimura and Tokine Yukimura, heirs to rival families of kekkai (barrier magic) users, who must defend their school from the spirits drawn to the sacred land upon which it is built.

A 52-episode anime television series adaptation produced by Sunrise was broadcast from October 2006 to February 2008.

Both manga and anime series have been licensed for English release in North America by Viz Media.

According to the legend, five hundred years ago, there was an insignificant lord who possessed a mysterious power that drew ayakashi (妖) (supernatural creatures) to him.

In the present day, Yoshimori Sumimura and Tokine Yukimura, heirs of the Hazama clan, are the kekkaishi (結界師) that protect Karasumori (which is located on the grounds of the school they attend).

Kekkai is a form of magical energy barrier which is primarily used to capture and destroy ayakashi that are drawn to this shin'yūchi (神佑地, "sacred land").

The ayakashi they must fight are becoming more and more powerful, but they managed to protect the land with the help from Yoshimori's older brother, Masamori Sumimura, and the Urakai (裏会, "Shadow Organization").

All the members are not the main inheritors of their clans lands or titles, or are loners who have no place to go, and thus have become a force that controls the course of their country.

However, being alone with no aid Tokimori was unable to completely seal off the Shinkai he created, which allowed Chūshinmaru's power to leak out, and it is this that draws ayakashi to the land.

[18] Kekkaishi was adapted by Sunrise as an anime television series directed by Kenji Kodama with character designs by Hirotoshi Takaya and music by Taku Iwasaki.

[34] The English edition of Kekkaishi was named by the Young Adult Library Services Association as among the best graphic novels for teens for 2007.