Aizawa Seiji is a twenty-eight-year-old single high school teacher suddenly transported with his entire class of thirty students to the throne room of the Ostrode Kingdom in another world. Princess Cassandra, a silver-haired beauty, kneels before them and begs the summoned “heroes” to save the world from the seven Demon Lords. An oracle foretold that thirty great lights would be their hope, and the thirty students are indeed those chosen ones. Seiji, however, is an accidental inclusion—an adult not among the thirty lights.Cassandra explains that everyone summoned possesses special abilities called Skills, and she performs an Appraisal using a giant crystal. The students, initially anxious but soon excited, line up to be tested. Nakatsugawa Shosei, the charismatic class representative, reveals the Cheat “Hero of Light” with Holy Sword and Light Magic. Shinohara Akane, the serious female leader, manifests as the “Witch of Lightning” with Lightning Magic. Other students display similarly powerful combat-oriented cheats. When Seiji’s turn comes, his appraisal shows only “Repair Level 1,” the ability to repair broken objects. The students tease him about his underwhelming skill, but he maintains a smile to keep morale high.A crucial question arises: can they return to Japan? Cassandra admits that with current magic, sending them back is impossible. Seiji steps forward as a teacher, acknowledging the reality of their situation but urging the students not to lose hope. He points out that among their thirty cheats, someone may eventually learn summoning magic, and they should work together to find a way home. His speech rallies the class; Nakatsugawa and Shinohara lead the group in accepting the mission to defeat the Demon Lords while striving for a return.That night, Seiji is given a private room. While examining his surroundings, he accidentally knocks over a vase. He tries to activate his Repair skill but fails, revealing his inability to use it instinctively.The next morning, Seiji puts on the kingdom’s enchanted military uniform, which magically adjusts to his size. He joins the students for breakfast served by cat-eared beastkin maids, then they are led to an audience with King Van Houten. The king welcomes them and entrusts their training to Knight Commander Ashcroft and Mage Division Commander Anastasia.During the first lesson, Ashcroft distributes “Rings of Possibility” that allow each user to visualize their cheat and ability status. Seiji’s ring again displays only Repair Level 1. The Knight Commander explains that cheats are divided into combat and support types, each has a unique weapon, and levels rise through experience. The students are enthusiastic about mastering their abilities.In the next lecture, Anastasia teaches the history of the kingdom and the reason for their summoning. She reveals that less than thirty percent of humans in that world are born with cheats, and a prophecy stated that hope exists in another world. A summoner magician brought the Japanese people who all possess powerful cheats—except for Seiji, whose weak Repair marks him as an irregular.As the classes proceed, Seiji silently accepts his role as the guardian and motivator of his students. Though his ability seems insignificant, he is determined to protect them and support their growth. The story begins their arduous training, with the thirty heroes learning combat skills and magic, while Seiji, the thirty-first person, faces the challenge of finding his own place and usefulness in a world where he is the only one without a heroic gift. Together, they set out on a journey to confront the seven Demon Lords and search for a way back to Japan.
