In the near future, Japan's Ryugan Island is overrun by mysterious giant beasts known as "Kyoju," forcing the human population to evacuate. To combat the creatures and reclaim the island, private pest-control companies deploy giant robots. One such company is Namidome Industries, a chronically underfunded small business run by president Koji Tajima. The story follows Tetsuro Okino, a young engineer and robot enthusiast who developed the advanced mecha Bullbuster at Crab Tech. Okino is transferred to Namidome as the mecha's pilot, but quickly discovers that defeating giant beasts is only half the battle. The company is perpetually on the brink of bankruptcy, and every bullet, drop of fuel, and hour of pilot overtime must be meticulously accounted for. Okino works alongside a small team: Arumi Nikaido, a cool and mysterious female pilot; Ginnosuke Muto, a veteran mechanic; Miyuki Shirogane, the company's efficient office manager; and Kintaro Kataoka, a strict accountant who enforces cost discipline. The manga's narrative arcs center on the tension between the heroic ideal of exterminating the Kyoju and the harsh reality of operating a business. Early episodes involve deploying Bullbuster for the first time under extreme budget constraints, and rebranding the company to improve public relations. A major arc involves a risky plan to capture a live Kyoju for research, which brings Namidome into conflict with Shiota Bio, a larger corporation with hidden agendas. As the story progresses, the characters uncover clues about the Kyoju's true origin and face threats of a hostile takeover. The series blends mecha action with workplace drama, emphasizing the financial and logistical challenges of running a zero-sum enterprise against monstrous odds.