Ryūichi Hiroki (廣木隆一 Hiroki Ryūichi) is a Japanese director, screenwriter, and editor. He began his career in the Pink film industry. Together with directors Genji Nakamura and Hitoshi Ishikawa, he founded the production company Yū Pro. Under the collective pen-name Gō Ijūin, the trio made a series of extreme S&M films for release by Nikkatsu in the mid-1980s. Along with the other two "Gō Ijūin" directors, Hiroki started making mainstream films in the 1990s.