Shuuichi, Sumire, and Katsumi all hailed from a government facility where people were subjected to experiments to enhance their telepathic skills. Their existence as research subjects was arduous, forcing them to flee for their freedom. Despite the years that have transpired, they remain fugitives, pursued by enigmatic organizations. Of the three siblings, Shuuichi is the most coveted, representing the "zero-sample" for his remarkable ability to incite "zero-shock."