Take all of the bad n’ stuff it into a little box and then crush that box and send it to another dimension.
Some 500 years ago the Karasumori clan possessed a special spiritual energy that caused Ayakashi (monsters/demons) to be drawn to them. The Karasumori hired a Kekkaishi (Barrier Master) to destroy the Ayakashi that appeared. Over time the spiritual energies of the Karasumori grew to the point that Ayakashi could feed off of the energy and grow stronger simply by being near. For some reason the original Kekkaishi fail to protect the Karasumori and the clan was wiped out but their enery remained behind, sleeping under the grounds of Karasumori castle.
Cut to present day where the original Kekkaishi’s house has split into to families, the Sumimura and theYukimura households. They continue to protect the grounds that Karasumori castle once stood on and prevent Ayakashi from feeding there and becoming powerful enough to hurt humans.
They fight by summoning small cube Kekkai (barriers) and are able to destroy anything contained inside the barrier.
The main story covers Yoshimori Sumimura quest to become strong. He’s driven by an incident from his past where his weakness caused a good friend to get hurt. Vowing to never let that happen again Yoshimori trains himself so that he can become powerful enough to not only be able to destroy any Ayakashi that enters Karasumori grounds but to seal the power of Karasumori itself.
The manga is a good read with a nice blend of action and comedy and the anime follows the manga prettly closely. Overall… some good stuff!