Yoshiro Shimezu — Samurai warrior, engaged in rebellion against the Shogun.
Kasimoto — Shogun, feudal lord controlling much of central Japan.
Goro Masamune — Japan’s greatest swordsmith, crafted the Honjo Masamune, considered the finest Japanese sword ever created.
Sengo Muramasa — Alleged to be Masamune’s apprentice, second-greatest swordsmith of historical era, crafted the Crimson Blade.
Wen Li — Powerful, shadowy figure in the Chinese government and Communist Party, shrewd strategist also known as the Lao-shi or learned Master.
Walter Han — Half Japanese, half Chinese, wealthy industrialist, sometimes proxy for Wen Li.
Mr. Gao — Han’s chief engineer, robotics and computer expert.
General Zhang — Important member of the Chinese secret service, head of the Ministry for State Security.
Rudi Gunn — Assistant Director of NUMA, graduate of the Naval Academy.
James Sandecker — Former head of NUMA, now the Vice President of the United States.
Kurt Austin — Head of NUMA’s Special Projects division, world-class diver and salvage expert, once worked for the CIA.
Joe Zavala — Kurt’s right-hand man, expert in design and construction of engines and vehicles, also an accomplished helicopter pilot and amateur boxer.
Paul Trout — NUMA’s lead geologist, also tallest member of the Special Projects team at six foot eight, married to Gamay.
Gamay Trout — Marine biologist, married to Paul, Gamay is a fitness aficionado, an accomplished diver.
Priya Kashmir — Multidisciplinary expert, was supposed to join a NUMA field team before a car accident left her unable to walk, assigned to the Rising Seas Project.
Robert Henley — NUMA geologist, assigned to the Rising Seas Project in Paul’s absence.
Kenzo Fujihara — Reclusive scientist, and former geologist, now leader of an antitechnologist sect, developed method for detecting Z-waves.
Akiko — Sergeant at arms for Kenzo, formerly connected to the underworld, acts as his protector.
Ogata — Member of Kenzo’s antitechnology sect.
Superintendent Nagano — High-ranking member of the Japanese Federal Police, assigned to the Fujihara case, expert on the Yakuza and organized crime.
Ushi-Oni — Former Yakuza assassin, now a rogue force, also known as the Demon, distant relative and sometime associate of Walter Han.
Hideki Kashimora — Yakuza underboss in charge of the Sento, an illegal gambling establishment and fight club on the outskirts of Tokyo.