The lost ones, who came from an alternative world known as "Japan", brought disaster to the world in the past. Menou is an executioner who is responsible to eliminate the lost ones.
Average student Mitsuki Mutou suddenly finds himself transported to another realm. Summoned by the king of this world for the remarkable power he is supposed to possess, Mitsuki is thrown out when it appears that he lacks a Special Concept. Moping about, he encounters a priestess named Menou who explains that Japanese people like him are known as Lost Ones, and such individuals never fail to have Special Concepts. Menou elaborates that she is part of a church that helps abandoned Lost Ones integrate into society. She invites him to spend the night at her church, where the two can probe the nature of his ability. Eventually, they discover that Mitsuki's Special Concept is actually incredibly powerful and dangerous. But is Menou's true goal to assist Lost Ones-or the opposite?—MAL Rewrite
The Lost Ones are wanderers who come here from a distant world known as "Japan." No one knows how or why they leave their homes. The only thing that is certain is that they bring disaster and calamity. The duty of exterminating them without remorse falls to Menou, a young Executioner. When she meets Akari, it seems like just another job...until she discovers it's impossible to kill this girl.—MeWatch
The Lost Ones are wanderers from a faraway world known as "Japan" who have brought disaster and misfortune into the present day. The responsibility to destroy them, therefore, belongs to Menou, the young executioner. However, Akari appears to hinder Menou's murderous progress. An amazing journey begins when Menou sets out to find a way to defeat the immortals .—Bilibili TV
The lost ones, who came from an alternative world known as "Japan", brought disaster to the world in the past. Menou is an executioner who is responsible to eliminate the lost ones. She met Akari, a Japanese girl, and embarked on a journey with her. During the journey, it seems that something inside the heart of Menou begins to change.—Ani-One