Hirai Tarō (1894-1965) adopted the pseudonym Edogawa Rampo because it sounded like a Japanese mispronunciation of "Edgar Allan Poe" and he was ambitious to be a writer of detective fiction. He was not the first Japanese writer to build a career in that genre, but he was a member of the first generation that was able to grow up reading crime fiction eclectically. Poe's detective stories were first translated in Japanese in 1887, and Arthur Conan Doyle's Sherlock Holmes stories began to appear there in 1899. Hirai's mother was a fan of the writer and translator Kuroiwa Ruiko, who adapted early French mysteries by such writers as Emile Gaboriau. By the time Hirai began writing in the 1920s there was a crime fiction magazine, Shin Seinen, to serve as a convenient marketplace. He continued to produce work in the genre for forty years, under various different influences.
In March, 1984, a team of criminals abducted Ezaki Katsuhisa, president of confectioner Ezaki-Glico, from his home in the Osaka suburb of Nishinomiya. After Ezaki escaped his captors unharmed, the gang embarked on a string of audacious blackmail attempts against food manufacturers in the Kansai region. In a stream of sarcastic letters to local newspaper bureaus, the criminals taunted the police. Their typewritten notes were signed Kaijin Nijūichi Mensō (The Mystery Man of Twenty-one Faces) — an unmistakable allusion to Edogawa Rampo's fictitious criminal mastermind, Kaijin Nijū Mensō (The Mystery Man of Twenty Faces), nemesis of detective Akechi Kogorō, whose exploits first appeared in an eponymous 1936 magazine serial.