The narrative follows Patience Granger, a 10-year-old girl who is actually the soul of a 25-year-old office worker from Japan. She awakens in Patience's frail body to find the Granger family in dire financial straits. The family consists of her father, Viscount William Granger, a scholar currently dismissed from his post and consumed by his studies; her younger brothers, 8-year-old Nascius, a bookworm, and 6-year-old Henry, an energetic child. Their mother, Julianne, died two years prior from pneumonia, a consequence of her delicate health and perhaps the family's poverty. The household staff includes the loyal maid Mary, the cook Eva, the butler Wyatt, and the under-servant George, along with his apprentice Matthew.
Upon awakening, the protagonist, now inhabiting Patience, is immediately struck by the family's extreme poverty and the cold. She learns that calling a doctor is a luxury, and her predecessor likely died from pneumonia due to the lack of proper heating and thin bedding. Driven by a desire to improve their living conditions and protect her brothers, she resolves to change their circumstances.
The early chapters detail Patience's struggle to adapt to her new life and body, grappling with the ingrained manners and habits of the original Patience while trying to implement practical changes. She discovers the family's lack of income stems from Viscount William's dismissal from his royal court position, leaving them without a salary. The family's meager meals, consisting of thin soup and bread, highlight their financial hardship.
A significant turning point occurs when Viscount William informs Patience that she must undergo a magic ability assessment at the church, as is customary for nobles before attending the Royal Academy. He believes she will possess "life magic," similar to her mother. This news sparks hope in the protagonist, who sees magic as a potential tool to improve their lives, particularly for tasks like cleaning and, crucially, for using the house's actual toilets, which require magic stones.
Patience, with Mary's assistance, begins to experiment with "beginner life magic," discovering its ability to clean and even restore worn items. She successfully revitalizes the children's room, impressing her brothers and Mary. The protagonist also learns that attending the Royal Academy is mandatory for nobles aged 10 to 16. This revelation causes her anxiety about her ability to fit in, given their poverty, but also presents an opportunity.
The narrative culminates in Patience's visit to the church for her magic assessment. She is confirmed to possess life magic, a common ability, which disappoints her slightly as she had hoped for something more extraordinary. However, this official recognition allows her to access the house's toilet and provides a basis for her to learn more advanced magic at the academy. The family celebrates this with a slightly improved meal, and the protagonist is informed that she must attend the Royal Academy, even if it means boarding there due to the distance and the family's inability to afford daily transport. This sets the stage for her future endeavors to improve her family's fortunes and navigate the challenges of noble society.