A budding engineer named Tetsurou Okino is assigned to a pest‑control firm, Hato Industries, where he brings his own creation, the Bullbuster robot. The modest company, led by president Tajima, faces a strange menace while operating on a tight budget. Costs for robot fuel, pilot wages, and the strict rule against wasting any ammunition weigh heavily on them. As their extermination ideals clash with fiscal limits, what lies ahead for Hato in the near future and uncertain prospects ahead?
