Chaos;Child unfolds in rebuilt Shibuya, where the scars of the "New Generation Madness" murders still linger. Those gruesome killings once pushed the district into mass hysteria, and at the height of the chaos a sudden earthquake reduced Shibuya to rubble while the surrounding wards remained strangely intact.
Six years later, the city has been rebuilt, but the calm is only surface-deep. The streets, schools, and storefronts look ordinary again, yet the memory of that outbreak of fear still hangs over the district like a shadow. When a new string of mysterious deaths begins to surface, third-year student Takuru Miyashiro notices a disturbing pattern: the dates of the recent murders match those of the original New Generation Madness incidents. That coincidence pulls him and several members of his school newspaper club into an investigation that quickly stops feeling like a story to report and starts feeling like a trap closing around them.
As they follow the thread deeper into the mystery, the case turns dangerously personal when they become trapped at the center of a fresh crime scene themselves. Old trauma and new violence begin to overlap, and the rebuilt city becomes a pressure cooker of fear, obsession, and secrets that refuse to stay buried.