The narrative picks up with Lady Asia Foregandros, a fourteen-year-old noble and the sole heir of the Foregandros ducal family, facing exile. Following the conclusion of the Kerdis War between the Gyliss Kingdom and the neighboring Isle Kingdom, a peace treaty was established that mandated the banishment of war heroes to ensure lasting peace and prevent future conflict. Despite her pleas of innocence, Asia is declared an S-class war criminal and sentenced to island exile. Her father, Duke Foregandros, died a hero in the war, and her mother, driven to despair by his death, committed suicide shortly after the war's end. Now, with her family's name and legacy at stake, Asia is thrust into a harsh reality.
She is transported by a Gyliss Kingdom warship to an uncharted island, revealed to be "Monster Island." This desolate, uninhabited island, located in the center of the three continents, is teeming with monsters and is not claimed by any nation. Asia's protests of illegal exile are ignored by the soldiers, who quickly depart, leaving her alone. Shortly after the warship leaves, a colossal Kraken attacks and sinks it, leaving Asia as the sole survivor on the island.
On her first day, Asia, despite her initial despair, resolves to survive. Armed with limited provisions and her knowledge from a children's book and overheard conversations about foraging, she ventures into the island's dense jungle. She discovers edible berries, which she shares with a small, squirrel-like monster she names "Lisuko," who becomes her first companion. Lisuko guides her to a tree laden with wild grapes, providing a much-needed source of food and hydration. As night falls, Asia constructs a rudimentary shelter against a cliff face using branches and large leaves, reflecting on her family and her determination to survive.
The following days are a struggle for survival. Her makeshift shelter collapses overnight, and she experiences the debilitating effects of eating a poisonous mushroom, which leaves her disoriented and weak. On the third day, while still recovering, she is discovered by Milos, a former mercenary from the Isle Kingdom and a member of the Lycanthrope tribe. Milos, who was also exiled to the island after his ship was attacked by monsters, offers Asia water and prepares a remedy from tree leaves to counteract the mushroom's poison. He explains that he is a demi-human and that his tribe, along with monsters and humans, are the world's inhabitants.
Milos, a skilled survivalist, demonstrates how to start a fire using obsidian and iron ore, a skill Asia also learns. He reveals that he is the sole survivor of his transport, having escaped a monster attack. He recognizes Asia's surname and her connection to Duke Foregandros, offering his condolences. Recognizing their shared predicament as exiles, they form an alliance to survive on the island.
On the fourth day, Milos senses an approaching rainstorm and suggests they reinforce their shelter and find a way to collect rainwater. They discover wreckage from a sunken ship, including a large piece of sailcloth, which they plan to use to improve their shelter. Asia, despite her initial fear and loneliness, finds a renewed sense of purpose and excitement in their collaborative efforts, embracing her role as a "secret base builder." The chapters conclude with Asia and Milos solidifying their partnership, ready to face the challenges of their shared exile.
