The story follows Sarana Kinje, a 13-year-old noblewoman who was unexpectedly engaged to the second prince of the Golda Kingdom. Her engagement was abruptly broken off by the prince, who claimed to have found true love with a commoner saint. The royal family supported this, eager to harness the saint's rare light magic. To save face, Sarana was given a fabricated reason for the annulment: her supposed frailty and inability to bear children, a fatal flaw for a noblewoman. Despite receiving a generous severance, Sarana, who is secretly a reincarnated soul from modern Japan, finds her social standing and future prospects ruined.
Her father, Seruto Kinje, a kind but indecisive count, is distraught by his daughter's predicament and the pressure from relatives to secure the family's lineage. He decides to abdicate his title and move to the neighboring Yulk Kingdom, a decision supported by Sarana's mother, Karna, who never truly fit into Golda's rigid aristocratic society. Karna's family, the Doyards, are welcoming and offer them refuge. Sarana, having foreseen her engagement's end and the subsequent social ostracization, agrees to the move, lamenting that her life has become devoid of the "villainess" or "comeback" story she expected.
Upon arriving in the Yulk Kingdom, Sarana and her family are warmly welcomed by her maternal uncle, Sieg Doyard, the current lord of the Doyard territory, and his family. Seruto is employed as Sieg's assistant, a role that suits his meticulous nature, while Karna and Sieg's wife, Michelle, reconnect. Sarana, now a baroness by marriage to her uncle's family, finds herself with ample free time due to her advanced education from her previous life and her prince-consort training. Bored, she begins exploring the village and reading the historical journals of past village chiefs.
These journals reveal valuable information about crop cycles and weather patterns. Sarana, using her analytical skills and the journals, predicts a harsh winter with heavy snowfall. Her prediction, based on observing specific natural phenomena like early snowmelt and the abundance of a particular flower, is initially met with surprise but is taken seriously by her family. This prediction allows the Doyard territory to prepare adequately, earning Sarana further respect.
Sarana's ingenuity extends to practical inventions. She develops a double-layered, insulated water bottle using materials from the local blacksmith and artisan, which is then patented and manufactured. She also creates a portable stove that utilizes "waste" magic stones, a common byproduct of monster hunting, to heat or cool. These inventions, particularly the magic stone-powered appliances, prove highly successful, generating significant income and solving the problem of waste magic stone disposal.
Her inventions lead to a partnership with the Alto Trading Company, managed by the young and capable Alto Saas. Sarana's business acumen and philanthropic approach, focusing on local artisans and the welfare of the common people, impress Alto. She also takes on the task of educating orphans at a local orphanage, teaching them literacy, arithmetic, and practical skills like sewing and crafting, enabling them to produce and sell goods, including down comforters made from monster feathers.
The story culminates with the impending visit of the Yulk Kingdom's young, unmarried King's younger brother, Prince Tori, who is known for his sharp intellect, swordsmanship, and a strong aversion to women, particularly eligible noblewomen. The Doyard family prepares for the royal visit, with Sarana, despite her past experiences, being tasked with overseeing the preparations due to her prior royal education. Prince Tori, however, misinterprets Sarana's presence at a planning meeting as an attempt to solicit marriage and dismisses her rudely, a reaction that intrigues Sarana and hints at future complications. Meanwhile, the King and Queen of Yulk, aware of Tori's stubbornness and his potential to miss out on a suitable partner, orchestrate the visit to Doyard territory, hoping Sarana's intelligence and unique qualities will capture his attention.
