Kensuke is the next in line to be head of the Dojoji clan. He is actually a snake demon and is the twin of his sister, Kiyo. Unlike Kiyo though, Kensuke has a soft side to him and doesn't wish to be as cruel as his sister is.
Kiyo convinces him to transfer to Misao's school and get close to her, so that her and Kuzunoha can trick Misao and take her away from Kyo. ~!!~