Ordinary student Mitsuki Mutou abruptly finds himself whisked into a different world. The ruler of this realm summons him, claiming he wields an extraordinary power; yet Mitsuki is dismissed when it becomes clear that he lacks a Special Concept. Feeling dejected, he meets a priestess called Menou who informs him that Japanese people like himself are classified as Lost Ones, and such beings always possess Special Concepts.
Menou explains she belongs to a sanctuary that aids forsaken Lost Ones in adapting to society. She offers him lodging for the night at her temple, where together they can examine his talent. In time, they realize Mitsuki"s Special Concept is exceedingly potent and perilous.
Yet does Menou truly aim to help Lost Ones—or something else entirely for the greater good ever?
