Kubota is in charge of development on World Children's Land, a place which promises "peace" to children. He is first seen giving the film's protagonist Gengo Kotaka, who is seeking a job, a "run-down" on the park and what it stands for. He tells him that the park will feature many statues of Monsters, leading to Kotaka pitching his idea for two new monsters that he feels children will react well to: Shukra: the monster of homework, and Mamagan: the monster of strict mothers. Kubota likes the idea, and signs Kotaka on to the project. They meet again when Kubota is leaving the development building in downtown Tokyo, but they have little time to converse because Kubota is chasing a thief. Kubota is unsuccessful in regaining the filched goods, and informs his employer Fumio Sudo. Sudo tells Kubota that it is not greatly concerning, and that they only need to shift some phases around in teir "master plan". Days later, Kubota finds Kotaka inside Godzilla Tower, sneaking around. Kubota asks why he is here and gives him some free cigarettes, because smoking was still okay in 1972. Kubota had put tracking devices in the cigarettes, and was able to follow Kotaku to he and his associates' base of operation where he finds and retrieves the lost tape. Shortly after, Kubota finds the protagonists in Godzilla tower, but this time brings them at gunpoint to the control room, where he and Mr. Sudo tell them that they will be used as "flesh suits", because their race is giant space cockroaches that must live inside dead humans to survive on earth. Kubota tells the humans that there was, on their home planet, a race much like the humans, but they polluted the planet to a point where the could not live on it, so they all dies, leaving only the M Space Hunter Nebula Aliens. Kubota dies in Godzilla tower with Sudo.