Hiraga Keaton Taichi is half Japanese and half British. He belonged to the SAS (Special Air Service) of the British Military, and he was an expert of survival technique. Now, he is studying archeology and works as a lecturer at the college. At the same time, he works for an insurance company as an investigator, and he travels around the world to investigate the incidents. There, he is often involved in troubles, but he solves them by his excellent knowledge and techniques.