A young engineer, Tetsuro Okino, is transferred to a vermin extermination company, Namidome Kogyo, with a new robot he developed himself, the "Bullbuster." Namidome, of which Tajima is the president, is confronted by a mysterious creature named "giant beast!" Moreover, being a small company that is short of money, Namidome is always faced with economic problems. ...... The cost of fuel for the robot and pilot labor costs - and of course, even wasting a single bullet is unacceptable. Between the "ideal" of killing the giant beast and the "reality" of cost, will there be a future for Namidome?

An anime TV series set in the city of Kitakyushu, Japan. The film is the result of the "Economically Correct Robot Hero" project, which brought together up-and-coming creators under visual director Hiroyuki Nakao and manga artist Eisaku Kubonouchi.