Yuuki, Shingo

The first member of the Kannagi family to meet Kazuma upon his return to Japan. Hired for the same job as Kazuma, to rid a wealthy man's home of a ghost, Shingo was initially demeaning of Kazuma as he believed Kazuma was as weak as he used to be.

[Spoiler] After jumping the gun and getting creamed by the yoma, Shingo was shaken to see Kazuma using wind magic. He's later killed by a wind magic user who he believed was Kazuma, as the assailant was hidden in the shadows.

His killer was revealed to be Ryuuya Kazamaki, who went on to kill his brother too. [/Spoiler]