A 36-year-old single home center employee named Masaru finishes a long day of construction work at a rural Japanese home improvement store. As he walks to his van, he is abruptly pulled into a white void and informed by a frivolous goddess named Victoria that he has been chosen as the prize for a bet she won against Zeus. Without any say in the matter, he is forced into the fantasy world of Alstatia, a realm that has stagnated for over four hundred years. Victoria grants him eleven skills, all production-oriented and seemingly low-grade, along with a physical restoration that de-ages him to 27 and slims down his previously overweight build.

Masaru awakens in a forest and is found by a cheerful rabbit-eared girl named Mei, who belongs to the rabbit-eared beastman tribe. A hobgoblin attacks them, and Masaru manages to defeat it through a combination of luck, his past experience in kendo and boxing, and his modest new abilities. Grateful for the rescue, the rabbit-eared tribe welcomes him into their settlement. Seeing their impoverished living conditions, Masaru decides to use his home center knowledge, DIY experience, and production skills to improve their village. He begins by constructing better housing, sanitation facilities, and tools, teaching the beastmen modern building techniques along the way.

To obtain materials that cannot be found inland, Masaru travels to a coastal village that once belonged to the rabbit-eared tribe but was taken over by hostile humans. He clears out the bandits and goblins occupying it, and when the coastal knight order arrives, he learns that displaced beastmen have been captured and sold into slavery. Determined to free them, Masaru heads to the coastal city of Portariim to negotiate with its representative, Lancelot, a legendary warrior known as a hero. Lancelot agrees to release the beastmen only if Masaru can demonstrate tangible results. Masaru undertakes infrastructure improvements such as sanitation upgrades and carriage redesigns, and when opposition to beastman liberation arises, he challenges Lancelot to single combat. Defeating the knight commander in a hard-fought duel, Masaru secures the freedom of the enslaved beastmen and a non-aggression pact between humans and beastmen.

Masaru returns to the rabbit-eared settlement with a human ambassador named Adelina, who becomes a close ally. As freed beastmen from multiple tribes arrive, Masaru proposes building a new town separate from the original village. While gathering materials in the forest, the group encounters a colossal demon bear, a monster regarded as a natural disaster. After careful preparation, Masaru and the rabbit-eared hunting party defeat it, securing the area for construction. The beastman town begins to take shape, with Masaru teaching carpentry, plumbing, and other crafts to the beastmen, who quickly become skilled builders.

A patrol of the Greitas Kingdom knight order, led by a captain named Fried, arrives wounded after being driven back by the demon bear, unaware it has already been slain. Learning of this, Masaru sees an opportunity and travels to the royal capital to negotiate directly with King Axion Fin de Greitas. The king initially treats him with disdain, but when Masaru casually summons the goddess Victoria and she calls him a friend, the king's attitude shifts to one of respect. A deal is struck, and Masaru uses his stay in the capital to purchase materials, livestock, and recruit skilled artisans, including a craftsman named Zailtaag, his sister Dina, and several retired adventurers seeking a new life.

On the journey back, Masaru rescues a group of dark elves from golems. Their queen, Emeralda, explains that their homeland of Stenzel has been overrun by mysterious golems. Masaru investigates, receives a divine request from the goddess Aila Sefira to deal with the golem threat, and ultimately destroys the golem-infested capital of Stenzel, ending the crisis. The surviving dark elves, including Emeralda and her knight Elena, settle in the growing beastman community.

As the settlement expands and attracts more species, a name is chosen by divine suggestion: Vinteria. With economic and political structures taking root, the inhabitants unanimously appoint Adelina as the first queen, founding the Kingdom of Vinteria. King Axion formally recognizes the new nation and signs an alliance with it, solidifying Vinteria's status in the world. The story follows Masaru's ongoing efforts to develop the kingdom, introduce advanced technologies, manage diplomatic relations, and confront the occasional monster threat, all while maintaining the slow-paced, free life he sought from the beginning. His relationship with Victoria also deepens over time, evolving from that of a divine observer and her summoned pawn into something more personal.