Sega Sammy Holdings
A magazine-book called "Undocumented the Rumble Fish ~Daremo Shiranakatta T.R.F.~" (Undocumented the Rumble Fish ～だれも知らなかったT.R.F.～) was published by Enterbrain and was an editorial collaboration between Arcadia Magazine, Sega Sammy Holdings, and Dimps. The publication features illustrations and concept art, background details about the game's characters and setting, and interviews and commentary from the game's staff, as well as technical data for each character.