A young engineer named Tetsurou Okino finds himself reassigned to Hato Industries, a pest control company, along with his own creation, the robot Bullbuster. In this small, financially constrained company led by President Tajima, a peculiar and unidentified creature poses a significant challenge.
With the cost of robot fuel, pilot labor, and a strict no-waste policy regarding ammunition, the company grapples with the conflict between their aspiration to exterminate pests and the practical constraints of their budget. What lies ahead for Hato as they navigate this balance between ideals and fiscal reality?