A modern Japanese agricultural high school student, Shizuko Ayanokouji, is suddenly transported back in time to the turbulent Sengoku period. She materializes in a forest and is immediately set upon by bandits but is rescued by a patrol led by the ambitious local daimyo, Oda Nobunaga. To avoid execution for suspicion of being a spy, Shizuko quickly demonstrates her worth by leveraging her specialized knowledge. She claims to possess the latest Nanban (southern barbarian) techniques for agriculture, a skill desperately needed to feed Nobunaga's growing army. Impressed, Nobunaga tests her by placing her in charge of a small, impoverished rural village.

As a student at an elite agricultural school, Shizuko has been rigorously trained by her grandfather, a famed agricultural scientist, and supplemented her education with a deep personal passion for Sengoku history. Her most valuable assets are the seeds of modern, high-yield crop varieties she happened to have in her bag and the encyclopedic, albeit theoretical, knowledge of farming, animal husbandry, and basic engineering. Initially, she struggles to earn the trust of the village's conservative elders, but her results quickly speak for themselves. Using techniques like crop rotation, fertilizer creation, and tool improvement, she transforms the village into a model of productivity.

Word of her success reaches Nobunaga, who becomes her primary patron. He assigns a retinue of samurai to guard her and assist in her projects, including the loyal and perceptive Keiji Maeda and the young, eager Nagayoshi Mori. Shizuko also befriends a starving wolf she names Wittman, who becomes her loyal companion and the progenitor of a loyal wolf pack. A mysterious amnesiac swordsman named Ashimitsu, who was also found by Shizuko's family in the modern era and traveled back with her, becomes her shadow and protector. It is later revealed that Ashimitsu is actually the former Shogun Ashikaga Yoshiteru, thought to be dead.

The story follows Shizuko as she introduces one innovation after another to the Oda clan, ranging from mundane yet revolutionary items like the family registry, hot baths, and shiitake mushroom cultivation, to more advanced concepts like blast furnaces for high-quality steel and even lever-action rifles. Her successes inadvertently accelerate Oda Nobunaga's rise to power, creating an alternate history where events unfold similarly but with crucial differences. Major historical battles, such as the clashes with the Azai-Asakura alliance, still occur but are altered by Shizuko's contributions, such as improved logistics, advanced weaponry, and new defensive tactics.

Key narrative arcs include the establishment of her technological village, her struggle to maintain her modern ethics while enabling a brutal warlord, and the political machinations that see her adopted into the nobility as Nihime. She also encounters other time travelers, such as a former salaryman named Mitsuo Tanaka, who uses his corporate knowledge to manage the clan's growing animal husbandry projects. As Shizuko's actions save the lives of figures who were meant to die and destroy others who were meant to live, the timeline diverges further from the history she knows, forcing her to navigate an increasingly unpredictable and dangerous political landscape. The series balances detailed, educational explanations of agricultural and industrial processes with the drama of a young woman trying to survive and thrive by radically reshaping the course of Japanese history.