Tokimori Hazama

Hazama Tokimori is considered the most well known kekkaishi due to the fact that he founded and passed on the kekkaishi ways. He was the first guardian of Karasumori. Tokimori was often confident to the point of cockiness. Instead of merely destroying or dispatching ayakashi, he sometimes captured and collared them, keeping them as pets, for no other reason than he had the power to do so. Because people had misunderstood his powers and considered him a monster in the past, he held a general contempt for them all, and became conceited as his power grew.

(Source: Kekkaishi Wikia)