The Executioner and Her Way of Life

Mutou Mitsuki, an ordinary student, finds himself abruptly taken to another realm. The monarch of this realm summons Mutou because of the supposedly amazing power he possesses, but Mutou is dismissed because it seems he lacks a "Special Concept." He runs into a priestess named Menou while moping around and she tells him that Japanese people like him are called Lost Ones and that they are characterized by having Special Concepts all the time. Menou clarifies that she belongs to a church that supports the social integration of abandoned Lost Ones. She extends an invitation for him to spend the night at her church so they may discuss the nature of his talent. They eventually learn that Mutou's Special Concept is actually very potent and hazardous. But does Menou really want to help the Lost Ones, or is it the opposite?