Muneto Ungyosai is a timid college student living in Tokyo and the son of a Buddhist temple master. He becomes a junior operative of the Interplanetary Mutual Observation Agency, an organization dedicated to monitoring and countering extraterrestrial threats. His motivations are rooted in a desire to protect those close to him, particularly Kayo Asakura, his high school love interest, whose body is uniquely suited to create human-alien hybrids. Muneto’s role in the story places him at the center of the conflict against the Demon Beasts, alien invaders seeking to colonize Earth through hybrid offspring. As a junior operative, he works alongside more experienced agents such as Shinichi Kasu and later Junichi Yagami, often struggling with his own lack of confidence and inexperience. His key relationships include his father, who interprets the alien threat as a manifestation of family karma, and his yamabushi uncle, Munechika Ungyosai, who provides spiritual and practical aid in the fight against the Hybrid. Over the course of the narrative, Muneto develops from a hesitant, ordinary student into a more active participant in the battle, though he remains defined by his emotional ties to Kayo and his sense of duty. His notable abilities are not explicitly supernatural; rather, he relies on his training as an Agency operative, his familial knowledge of Buddhist traditions, and his growing resolve to confront the invasion.