Shin inhabits the abandoned ruins of post-collapse Tokyo, where he oversees parkour team battles organized by resource-hungry youths in the aftermath of the Bubble Fall catastrophe. These high-stakes competitions dictate the distribution of scarce supplies among rival factions. As one of the city’s few remaining adults, he enforces impartial rules within the chaos, balancing structured oversight with the freedom for younger generations to redefine their fractured world. His characterization includes a matter-of-fact disability seamlessly integrated into his daily life, acknowledged without narrative fanfare. Shin’s role centers on maintaining equilibrium in the emerging societal hierarchy, ensuring survival through regulated conflict rather than personal ambition.