The debt-bound boy Kai was forced to enter the Mech Beast Arena with UNIT-09, a decommissioned robot. In a desperate fight, 09 absorbed scrap metal and transformed into a combat mech, defeating the champion but exposing its identity as the last surviving first-generation unit. Sera, an ace mech pilot, was ordered to hunt them down. Through 09's memories, Kai discovered his late father Aaron's final message and uncovered hidden truths behind the massacre twenty years ago. As the electromagnetic net closed in, 09 stayed behind to save Kai, its mirrored eyes going dark. After Kai plunged into the Magnetic Storm Canyon, could he save the only family he had left?