Minami Asaka, the Spandexer, discovers the existence of the legendary artifact Stone Gate, capable of warping spacetime, and heads to Mount Fuji alongside Dr. Murata, a researcher of out-of-place artifacts. However, Klein, a high-ranking member of the criminal organization Goban, learns of this through a spy and intercepts Minami, attempting to seize the Stone Gate. Minami fights back using the power of the Spandexer, but struggles against Klein's newly developed powerful mutants. Taking advantage of the chaos, Klein steals the Stone Gate and delivers its power to General Getto and his elite guards of the evil empire Gelhardt, ultimately unleashing an army of villains upon Earth, triggering a tragic chain of events.