"Who are you?" Hiraga Saito wakes up and sees a beautiful girl asking him this question. Looking around, he realizes that he is in an unfamiliar place; people dressed as wizards surround him and the girl. The girl, introducing herself as Louise, explains that she called him from his world as a "familiar". Misunderstanding of Saito increased, Especially after ,. How she kissed him and said , "It's my first kiss!" he shouted. but before , He had a chance to get angry. CM strange characters appear on his left hand, Marking it , As a familiar! During the search for the road home Saito must come to terms with it, that will live with Louise under the same roof as her familiar... Thus begins the comedic life of Hiraga Saito as "Nulizin's Familiar".