Craft, a sixteen-year-old adventurer with a mage's crest on his left hand, is unceremoniously kicked out of his party for his abysmal magic power, despite possessing immense magical energy. His party leader, Marboro, and the ranger Marietta express their disappointment, questioning if his crest is even genuine. Craft, unable to refute their valid criticisms, accepts his dismissal and heads to the Adventurer's Guild. The receptionist, accustomed to his repeated failures, suggests he's not suited for adventuring.
The guild, recognizing his lack of combat prowess, offers him a position in the Production Guild to help establish a new settlement in the frontier territory of Lord Bailord. Seeing this as a new path, Craft accepts. He arrives at the bustling Production Guild, where he meets the Guild Master, a burly man who assigns him to the settlement project. During the paperwork, the Guild Master, noticing Craft's mage crest and his inability to cast powerful spells, suggests a crest aptitude test. To Craft's astonishment, the test reveals that the mage crest is fundamentally incompatible with him, potentially even life-threatening. The test also reveals his true aptitude: a "Twilight Alchemist," a legendary and immensely powerful alchemist.
Craft's crest is transformed, bathing the guild hall in golden light. He gains immense magical power and the ability to perform "Spatial Storage," a rare magic that allows him to store vast amounts of items. The next day, he meets his fellow guild member for the settlement, a cheerful and surprisingly strong dwarf girl named Leefan. Their departure is marked by the arrival of Lord Bailord's second son, Zaid, and his younger siblings, Kyle and Mina, who will be the settlement's overseers. Zaid, clearly intending to set his brother Kyle up for failure, assigns him to the dangerous frontier. Witnessing Kyle's plight, which mirrors his own past struggles, Craft impulsively vows to ensure the settlement's success.
During the journey, Craft's alchemical prowess becomes evident. He creates "Stamina Potions" that grant incredible endurance and speed, allowing the settlers and even the horses to travel at an unprecedented pace, completing a month-long journey in just a week. His potions also prove effective against monsters, as he single-handedly defeats a large group of orcs, obtaining valuable magic stones needed for crafting. He also discovers his "Spatial Storage" is exceptionally powerful, capable of storing entire wagons.
Upon arriving at the settlement site, a fertile plain with a nearby forest and river, they find remnants of a former dwarven village. Craft, with his newfound abilities, helps establish the village rapidly. He creates a well using dowsing magic and his potions continue to boost the settlers' stamina and morale. He also discovers his potions have an incredibly long shelf life and can even be mixed with water.
As the village grows, Craft continues to develop his alchemy, creating healing potions and assisting with construction. He forms a close bond with Kyle, the young overseer, and his sister Mina, who is shy but seems to trust him. The skilled guards, Alphard and Persia, are initially skeptical of Craft's abilities but are eventually convinced by the effectiveness of his potions. The story concludes with the settlers working diligently to build their new home, with Craft's alchemical skills proving indispensable to their success.