Irimote operates as an operative for the Interplanetary Mutual Observation Agency, specializing as a Demon Beast Buster. This agent is deployed to a remote Ryukyuan island currently hosting a school trip. The core mission objective is the extraction of human protagonists Kayō Asakura and Muneto Ungyōsai from the Hybrid, an adult alien offspring actively executing invasion plans. Irimote intervenes at the critical moment during the Hybrid's climactic chase of Kayō and Muneto across the isolated island terrain.