Kogoro Akechi (明智 小五郎 Akechi Kogorō) is a fictional private detective created by Japanese mystery writer Edogawa Rampo.
Akechi first appeared in the story "The Case of the Murder on D. Hill" (D坂の殺人事件 D-zaka no satsujin jiken) in January 1925 and continued to appear in stories for a quarter of a century. Edogawa Rampo (a pseudonym for Tarō Hirai) is considered the father of the Japanese detective story and was a great admirer of Sir Arthur Conan Doyle. Akechi is the first recurring detective character in Japanese fiction and is clearly inspired by Doyle's Sherlock Holmes.
Like Holmes, Akechi is a brilliant but eccentric detective who consults with the police on especially difficult cases. He is a master of disguise and an expert at judo whose genius lets him solve seemingly impossible cases. Also like Holmes, Akechi makes use of a group of young boys to gather information. His version of the Baker Street Irregulars is known as the "Boy Detectives Club" (少年探偵団 Shōnen tantei dan). Akechi smokes Egyptian cigarettes when he is thinking about a case.