Omamori Himari, Vol. 7

Forced to stand by and watch as Himari faces off against an onslaught of
monsters ordered to attack by Tamamo-no-mae, Yuuto finally accepts his
role as a demon slayer! But acceptance doesn't automatically make him
good at it, and the young warrior must continue training to become
master of his own potential! And during one such training session, Yuuto
runs into another sleuth-like slayer, Hitsugi Yakouin! Will Yuuto learn
a thing or two about using his own Light Ferry powers with her?