The Battle Fever saga begins when FBI agent Diane Martin is sent to Japan in pursuit of an assassin. There she encounters the help of Japan's Ministry of Defense special task force, lead by Kurama Tetsuzan Shogun. He and Diane's father, the FBI director, unveil that the assassin is a member of a secret cult known as Egos. The Egos cult, under the leadership of their evil war god, Satan Egos, had
