I explore the history of Japanese writing centered on Sherlock Holmes as a means of interrogating the 2014 BBC Sherlock pastiche John and Sherlock Casebook 1: Jon, zenchi renmei e iku (The stark naked league), written by Japanese Sherlockian Kitahara Naohiko for mainstream publication by the publishing house Hayakawa shobō. I argue that exploration of the Japanese (fan) cultural contexts of Kitahara’s book begins to reveal the limits of the Anglo-American-centered framework through which fan studies scholars explore fan/producer relationships.