Makai Tantei Meiousei O

The belief that humans are at the top of the food chain is incorrect. A hidden group, referred to as "Them," exists in the darkness and avoids contact with the human world. They dislike being known to humans and include beings that resemble humans and others that do not. Occasionally, conflicts arise between humans and "Them," such as when humans discover their existence or when "Them" act against humans. To address these issues, a specific individual is called upon—Pluto O. Those in need can summon him by saying his name three times. The series was published under the name Echizen Matarou, with the actual authors' identities later disclosed by Kodansha, though not individually attributed. It was a joint project between Kodansha and Kadokawa, with books released through three different labels.