Ranpo is a young man with a fair complexion and short, messy black hair. His eyes, which are closed most of the time, are brown. Ranpo is a member of the Armed Detective Agency. Despite not being an ability user, he is known as one of the best detectives highly sought by the police, renowned by his comrades, himself, and others as the "greatest detective in the world." His uncanny aptitude, self-named "Ultra Deduction" allows him to deduce the "truth" about any crime.