Nico Wakatsuki finishes her training as a witch and comes home to start high school, and she and her childhood friend Morihito Otogi end up under the same roof. Morihito is an ogre in human form whose family has served the Wakatsuki witches for generations, so acting as Nico's familiar and bodyguard is inherited work, not a choice. Nico would rather the arrangement turn into a romance; Morihito gives her nothing to work with. Her magic, cast with far more enthusiasm than control, keeps misfiring and drops the two of them into one supernatural mess after another.