The story begins with the protagonist, a 40-year-old salaryman named Kurusu Daiki, being unexpectedly summoned to another world along with nine other individuals. These companions are all teenagers, consisting of five boys and five girls, each with distinct personalities and perceived roles: a studious "glasses-kun," a delinquent-like "yankee-kun," a disheveled "otaku-kun," a handsome "ikemen-kun," a serious "iinchou-chan," a flashy "yankee-chan," a sporty "rikujou-chan," an ordinary "futsuu-chan," and a science-oriented "rikei-chan." They are greeted by a portly king and his three princesses, along with numerous knights.
The king explains that their kingdom is on the brink of destruction due to an invasion by demons and requests the summoned individuals to save them. Their first task is to have their "blessings" or classes appraised using a crystal. The otaku-kun is revealed to be a "Great Magician," and the ikemen-kun is a "Hero." Daiki, however, receives a peculiar blessing: "My Home Base." This ability allows him to connect to a base in a subspace, with its size and facilities dependent on his magic power. He can also conjure water, food, weapons, and tools through magic conversion.
The king then divides the summoned individuals. The Hero, Great Magician, and a Sage (glasses-kun) are taken away with the princesses, while the remaining individuals, including Daiki, are deemed to have "useless blessings" and are ordered to be exiled to a neighboring country. The yankee-kun, now identified as a "Samurai," protests but is quickly subdued by the guards. The king reveals a cruel custom: summoned individuals who die an unnatural death in a neighboring country cannot be summoned there again, implying they intend to have the exiles executed at the border.
Daiki, realizing his "My Home Base" ability is crucial for survival, decides to take charge of the seemingly useless group. He offers them a place in his "harem" for protection, a proposition met with rejection by the "Saint" (rikei-chan) and the "Martial Artist" (iinchou-chan). The Saint, named Misuzu, chooses to follow Daiki, as does the Martial Artist, Kasumi. The group is given 15 days' worth of emergency rations, which the yankee-kun immediately seizes. Daiki, confident in his ability to produce food from his Home Base, allows this, and the three, along with the remaining exiles, depart in carriages.
During the journey, Daiki begins training his magic, while Misuzu and Kasumi also start exploring their abilities. They discover they can view their own status details and that Daiki's Home Base allows him to create a door to his subspace. He uses this to access his base, which resembles a hotel lobby, and prepares a meal for himself, Misuzu, and Kasumi. They learn to create doors to specific facilities within the Home Base, like a toilet and shower room, allowing them to maintain hygiene even while traveling.
Over the next week, they establish a routine. Daiki focuses on training his magic and developing weapons and armor from his Home Base, including firearms like a UZI and handguns. Misuzu, as a Saint, learns various healing and defensive spells, while Kasumi, as a Martial Artist, becomes incredibly strong, surpassing even Daiki and Misuzu in combat prowess. They also discover that their Home Base has a level system, allowing for more advanced creations as it grows.
Meanwhile, the other exiles, led by the arrogant yankee-kun and his companion, the yankee-chan, struggle with dwindling food supplies and poor hygiene. They eventually approach Daiki's group, seeking to join them, but are met with firm rejection due to their past actions and the yankee-kun's offensive odor. Daiki uses his UZI to intimidate the yankee-kun, and Misuzu heals his wounds, solidifying their group's resolve to rely on each other. The story concludes with the group continuing their journey towards the border, facing the unknown challenges of this new world.
