Commander Sugata discovered the existence of the Royal Underground Empire Tube, a malignant force that desires to dominate the land, which is based underneath Japan. He recruits five young people, each one specializing in a style of martial arts, and teaches them in the ways of the mystical "Aura Power" energy. A year after he recruited and trained the Maskmen, Tube is ready to strike.
911 receives a call from a young woman reporting the death of an acquaintance at a hotel, and Detectives Ushio and Ogami of Shinjuku West Police Station rush to the scene!! The caller is eventually identified as Megumi, a woman whom Detective Ushio's wife Sumie had met by chance, but Megumi too has been killed...
Three young country boys are beginning to drift apart as friends. In the summer, they set off to have an adventure in the mountains.
