Taishou Roman Haikara Tantei Aoi Ruby Satsujinjiken (大正浪漫 ハイカラ探偵王 青いルビー殺人事件), the full official title being Gekidan Gekiharo Dai 10kai Kouen "Taishou Roman Haikara Tantei Aoi Ruby Satsujinjiken" (劇団ゲキハロ第10回公演 ｢大正浪漫 ハイカラ探偵王 青いルビー殺人事件｣), is a stage play starring Tanaka Reina, Shimizu Saki, and Sudo Maasa. It was the tenth collaborative theater work between Gekipro and Hello! Project as Gekiharo. The screenplay was written by Kato Junya and the play was directed by Konaka Kazuya. It was also produced by Andrew Tamon Niwa and Sasaki Junko.