Kaku Kaioh, originally Guo Haichuang, reigns as the Supreme Grandmaster of Chinese Kenpo and Kaioh of Kaiohs. Exceeding 146 years of age, he is the undefeated champion of the Raitai Tournament for over a century, serving as China's team captain. His physical form is that of a shrunken elder, standing 155 cm tall and weighing around 40 kg, marked by long white hair, deep wrinkles, and gnarled fingernails. He typically wears a Chinese cap, round glasses, a light-colored tangzhuang jacket, pants, and kung fu shoes, relying on a wheelchair outside combat. This frail state sharply contrasts his youth, when he possessed a massive, muscular physique akin to Biscuit Oliva, complete with black hair in a traditional topknot. In his early years, Kaku was an arrogant bodybuilder who proclaimed himself Asia's strongest, dismissing martial arts philosophy. He fought countless wild animals and fighters until defeated by an elderly Chinese martial arts master. This loss led him to abandon weight training and dedicate himself entirely to Chinese Kenpo. Decades of this pursuit caused his body to atrophy to its current state as he embraced the principle of "weakness overcoming strength." His son, Shunsei Kaku, became a martial artist under his influence. Kaku exhibits a complex personality blending ruthless pride in Chinese martial arts with strategic cunning. He displays sociopathic tendencies, stabbing and dismembering three Chinese Martial Arts Association elders for perceived failures. He manipulates tournament lineups, replacing two Kaious with his son and a friend to secure China's victory, even threatening to kill his own son after a defeat to protect the team's reputation. He shows scant emotion, having sacrificed life's pleasures in his relentless quest for strength, respecting only Yuujirou Hanma for nearly killing him. Later appearances reveal a more approachable, even comedic side, particularly while training Katsumi Orochi. His martial prowess centers on Xiaoli (Shaori), a technique inducing hypoesthesia to absorb, contain, and redirect an opponent's force. Defensive Xiaoli nullifies incoming damage, while Offensive Xiaoli channels absorbed energy into devastating counterstrikes. Though physically debilitated—struggling to lift chopsticks—his Xiaoli mastery allows him to challenge top-tier fighters. He demonstrates supersonic striking speed, precision to slice objects like eggs, and durability to withstand punches from Yuujirou. His tactical ingenuity includes faking clinical death by stopping his heart to evade lethal blows. Additional techniques encompass the "Hitless Blow" and limb-severing chops. He identifies fighting styles through keen observation and adapts strategies mid-battle. Kaku's narrative spans significant arcs. During the Great Chinese Challenge Saga, he defeats Kaioh Samwan with a groin strike and allies with fighters against American-Japanese opponents. His climactic bout with Yuujirou Hanma showcases Xiaoli's potential against overwhelming strength, though he ultimately survives by feigning death. Later, in the Hanma Baki series, he assists Retsu Kaioh in training Katsumi Orochi, contributing to the "Countless Joints" technique by merging Chinese Kung Fu with karate principles. Personality analyses categorize him as ISTP or INTP in MBTI frameworks and Enneagram Type 8w9, reflecting analytical thinking, independence, and an unyielding pursuit of martial perfection. He draws inspiration from past failures and life experiences, maintaining vast knowledge accrued over a century of combat and philosophy.