Born in Nagano Prefecture, Yamaguchi graduated from Waseda University and began working at the Tōei studios in Kyoto. He directed a number of action movie series in the 1970s and has also helmed many TV movies.
When Koryu's childhood friend Shurei is abducted by gangsters, the desperate young woman recruits a female martial artist and a tough-as-nails stranger to join her for a dangerous rescue mission.
Li Mansei is a martial-arts champion turned undercover agent. When he is captured by a drug lord, his sister Li Koryu turns to his former martial-arts school, including the powerful Sonny Kawasaka, for help in the inevitable battle royale.
Akira Inugami is the only survivor of a clan of ancient werewolves who relies on his supernatural powers to solve mysterious crimes. After a series of bloody killings perpetrated by an unseen force, Inugami uncovers a conspiracy involving a murdered cabaret singer, corrupt politicians, and a plot by the J-CIA to harvest his blood in order to steal his lycanthropic powers.
