The protagonist, Itonami Norio, a salaryman, is suddenly transported from his mundane life to a medieval-European-style castle in another world. He discovers he is one of ten individuals summoned as "Heroes" by King Genesis XVIII to fight against a demon race that has been at war with the human kingdom for centuries. Each summoned individual is tested for "skills," which are divine blessings unique to those from other worlds. While most of the summoned individuals possess powerful skills, Norio is identified as having "None."
Disappointed, the King explains that while they can summon heroes, they have no way to send them back. The only known method to return to their original world is held by the Demon King. Faced with this predicament and unable to contribute to the war effort due to his lack of skills, Norio negotiates with the King. He requests a plot of land, preferably a desolate area far from the city, where he wishes to live peacefully. The King, somewhat relieved to be rid of a "useless" hero, agrees, granting Norio ten gold coins as preparation money, which he can use to purchase land. Norio cleverly negotiates to keep one coin for himself and use the remaining nine for land.
Norio renames himself "Kidan" to better suit his new life and travels to the purchased land, which turns out to be a vast, uninhabited wilderness at the edge of the kingdom, bordering the sea. He is left to his own devices, with the guide stating that the kingdom will have no further involvement with him. Kidan, who prefers a peaceful life of self-sufficiency and development over adventure, embraces his new life. He uses his remaining gold coin to purchase basic tools for farming and construction.
He soon discovers that he possesses a hidden power, a "Gift" from the god Hephaestus, the god of creation. This Gift, named "Supreme Carrier," allows him to become a master of any tool he wields and enhances the abilities of objects he touches. Hephaestus, who was temporarily managing summonings due to issues with the usual deity, bestowed this powerful Gift upon Norio as an experimental measure. This Gift is so potent that the kingdom's skill-reading magic cannot detect it, classifying him as "skill-less."
Kidan uses his Gift to rapidly clear land for farming and build a simple shelter. He discovers that touching soil with his Gift causes seeds to sprout instantly, even without planting them. He also finds that touching seawater with his Gift purifies it into fresh water, and the salt is separated, providing him with both drinking water and a source of salt. He begins cultivating various vegetables and foraging from the sea for food, encountering unique sea creatures with unusual characteristics.
While exploring the nearby mountains for resources, Kidan encounters a monstrous boar with horns and enlarged tusks. Using his Gift, he transforms into a master swordsman with a machete, defeating the creature. However, his weapon breaks, leaving him unable to process the meat, and he decides to leave the carcass to nature. He learns that the mountains are dangerous and decides to focus on the sea for food.
Later, while fishing, Kidan catches a mermaid named Purati. Initially hostile, Purati claims she must become his wife as a form of atonement for being caught by a land dweller. She reveals she can transform her fish tail into human legs using a potion, making her appear as a beautiful human woman. Despite Kidan's reservations about interspecies marriage and her forwardness, he reluctantly accepts her presence, and she moves in with him. Purati reveals herself to be a master of potion-making, a unique mermaid magic, and immediately begins assisting Kidan by creating a powerful fertilizer from a giant fish-like monster, which causes his crops to grow at an astonishing rate.
