The One-Eyed Monster's Human Review Operation! (一つ目怪人の人さらい作戦！ Hitotsume Kaijin no Hitosarai Sakusen!) is the fifth episode of Kamen Rider X. It introduced Tobei Tachibana, ally of the first four Kamen Riders, to the series, marking the instance Keisuke Jin learned of his predecessors who would appear to help him in his fight against G.O.D. later on.