Gouki Shibukawa, a Japanese martial artist known as "the Master," excels in Shibukawa-ryu Jujutsu and Judo. He is 75 years old, stands 155 cm tall, and weighs 47 kg, with grey hair and an artificial left eye from a past injury. His traditional attire is typically a white keikogi shirt and black hakama pants. Trained before World War II, Shibukawa served as a soldier and assassin during the conflict, developing a ruthless combat approach. His intensive study under master Kihei Mikoshiba culminated in a deadly confrontation where Mikoshiba, sensing lethal intent, slashed Shibukawa's back with a katana. This event marked Shibukawa's declaration of mastery and the founding of his own dojo. Shibukawa displays a calm demeanor punctuated by calculated violence, often feigning frailty—like pretending to need restroom breaks or throwing cold water disguised as hot—to unsettle opponents. He holds a traditionalist view, rejecting pre-fight warm-ups, believing true combat readiness is constant. Pragmatically, he incorporates unconventional tactics like headbutts, asserting "there is no such thing as a fair fight." His philosophy emphasizes redirecting an opponent's force against them, epitomized by his signature Aiki technique. In the underground Maximum Tournament, he defeated Olympic wrestler Roger Harlon by targeting pressure points and karateka Koushou Shinogi by countering the "Cord-Cut" technique despite Shinogi damaging his artificial eye. His subsequent match against Doppo Orochi ended with Shibukawa prevailing via a decisive throw, though he later expressed respect for Orochi's skill. He advanced to the semifinals but lost to Jack Hammer, whose brute force and mass negated his Aiki. Beyond the tournament, Shibukawa allied with Baki Hanma to confront Ryuukou Yanagi, the assailant responsible for his eye injury. He later engaged in a friendly spar with Biscuit Oliva and fought Mohammad Alai Jr. His combat abilities include extrasensory perception generating subconscious danger-warning illusions and pain suppression. He ranks among formidable fighters, capable of defeating larger opponents through technical precision.