Okino Tetsurou, a youthful engineer who created the advanced robot Bullbuster, is reassigned to Hato Industries - an enterprise committed to eradicating harmful creatures. The industry and its CEO, Tajima Kouji, confront a perplexing entity known as "Kyoujuu." Operating on a budget, Hato endeavours to manage expenses such as fuel and pilot compensation. The company is frequently torn between their staunch goals of completely eradicating Kyoujuu and their economic constraints, where mishandling their shots is unacceptable.