The story takes place on Earth nearly a thousand years in the future. After a devastating war between artificial intelligence and humanity, monstrous creatures known as "Tai Sui" roam the land, drastically altering the natural environment and social order. In response, humanity developed "BOX"—a series of advanced technologies related to mysterious boxes. These "Beast Boxes" became humanity's key allies in the fierce resistance against their enemies.

Elites capable of "resonating" with their Beast Box partners are known as "Beast Box Masters." Among them, a once-overlooked Beast Box Master named Liu Ma is unexpectedly chosen by a small dinosaur-like Beast Box named "Dio." Together, they begin their mission to protect the city-state. During grueling training, Liu Ma meets several other Beast Box Masters and their Beast Box companions. The group is soon tasked with reinforcing "Vermilion City," marking the beginning of their epic journey.