Ranpo Edogawa has fair skin, messy black hair, and typically closed eyes—brown in the manga, green in some adaptations. His attire evolves across story arcs, often featuring a brown deerstalker hat, matching inverness cape, three-quarter-length pants, and long white socks. Key to his look are black glasses, given by Yukichi Fukuzawa, which he uses to activate his deductive process despite lacking supernatural properties. Early depictions show him in a gakuran uniform; later storylines include disguises like a teddy bear costume during undercover work or a cloak and gas mask during the Agency's frame-up. Ranpo displays overt childishness masking profound depth. He frequently exhibits arrogance, proclaiming himself the "greatest detective in the world," and immaturity through laziness, refusal of mundane tasks, and teasing colleagues. This behavior stems from underlying trauma caused by exposure to violent cases and human suffering, serving as a coping mechanism. He shifts to intense seriousness during crises, such as protecting the Agency from threats like Fyodor Dostoevsky or the Decay of the Angel. Deeply loyal to the Armed Detective Agency, he views its members as irreplaceable friends whose faith fuels his resolve to shield them. Ranpo lacks common sense, struggling with basic activities like navigating public transit without deduction, yet compensates with exceptional memory and observational acuity. His deductive prowess, self-dubbed "Super Deduction," allows instant solving of complex mysteries by extrapolating truths from minimal clues, applicable to crime scenes, strategy, or interpersonal scenarios. This is not supernatural but the product of innate genius inherited from his parents: his father, a legendary detective known as the "Clairvoyant," and his mother, whose intellect surpassed her husband's. For years, Ranpo clung to the belief his skills were ability-based, a delusion encouraged by Fukuzawa to help him navigate an alienating world. After the Yokohama fog incident, he gradually accepted his non-ability status, though he occasionally still uses the glasses as a psychological aid. His deductions remain infallible within canon, enabling him to outmaneuver adversaries like Mushitarō Oguri, who specialized in erasing evidence. Orphaned young, Ranpo was raised in rural isolation by his genius parents, who normalized extraordinary intellect, leaving him unprepared for societal norms. After their deaths, he moved to Yokohama; his inability to relate caused repeated job failures until encountering Fukuzawa during a corporate assassination case. Fukuzawa's lie about Ranpo's "ability" provided stability. Their partnership culminated in founding the Armed Detective Agency, with Ranpo as its first member. Sōseki Natsume later aided them in securing a Skilled Business Permit. Ranpo's development shows in his evolving approach to vulnerability and leadership. Early reliance on the "ability" delusion shifted post-Cannibalism arc, where he acknowledged fallibility after failing to prevent Fyodor's schemes. This drove him to study Fyodor's methods, recruit former enemies like Mushitarō, and devise contingency plans, demonstrating strategic growth beyond pure deduction. His emotional resilience solidified through interactions with allies like Edgar Allan Poe, a former rival turned collaborator, and inspiring loyalty in others—such as persuading 30% of Yokohama's police force to aid the Agency during their frame-up. Central to his arc is reconciling his non-ability status with his role among gifted colleagues, using intellect to protect rather than dominate, exemplified when assuring Akiko Yosano of her worth beyond her ability during her traumatic past.