A private plane carrying students and staff from a Japanese high school crashes on a mysterious island during a return trip from a school trip. The survivors, led by Akira Sengoku, a delinquent with a strong sense of justice, quickly realize the island is unlike anything they have encountered before. It is populated by prehistoric creatures, including dinosaurs and other extinct species, as well as strange, futuristic ruins that suggest advanced human activity. The group must navigate this dangerous environment while searching for answers about the island’s origins and a way to escape.

As the survivors explore the island, they encounter other groups of people who also crashed under similar circumstances, leading to alliances and conflicts. Tensions rise as resources become scarce, and the group faces internal power struggles, moral dilemmas, and the constant threat of deadly creatures. Akira emerges as a natural leader, often clashing with others, such as the pragmatic and calculating Rion Akagi, who prioritizes survival over morality. The group also includes characters like Mariya, a resourceful and intelligent girl, and Zaji, a former soldier who provides tactical expertise.

The narrative delves into the mysteries of the island, revealing clues about its purpose and the fate of its previous inhabitants. The survivors discover that the island is part of a larger experiment, possibly tied to a dystopian future or a secretive scientific project. Flashbacks and cryptic messages hint at a connection between the island and the survivors’ own timeline, raising questions about time travel, alternate realities, and the ethics of scientific experimentation.

As the story progresses, the group uncovers more about the island’s structure, including underground facilities and advanced technology. They face increasingly dangerous challenges, including encounters with hostile humans and genetically engineered creatures. The survivors’ relationships evolve, with trust and betrayal playing key roles in their struggle to survive. The series balances action, mystery, and character development, exploring themes of survival, human nature, and the consequences of unchecked ambition.

The manga concludes with the survivors piecing together the island’s secrets and making a final attempt to escape. The ending ties together many of the story’s mysteries while leaving some questions open to interpretation, providing a satisfying yet thought-provoking resolution to the series.