Morihito Otogi, a high school student from a family of ogres, lives a peaceful and normal life until his childhood friend Nico moves in with him. Nico is a witch in training and Morihito chooses her to be his familiar. Nico is excited to reunite with and crush on her old friend, and Morihito has the dangerous task of protecting her from a predicted disaster. Between the unexpected chaos caused by Nico’s magic and the difficulty of sharing a house, their lives become a whirlwind of mysterious mischief and threats.