Description
Kaioh Jaku, also known as Jaku Kaioh or Sea King Jaku, holds the prestigious title of Kaiou (海王), awarded to martial artists of exceptional skill by entities like the Chinese Martial Arts Association or an existing Kaiou. A Japanese national, he works as a martial arts instructor actively recruiting Kaiou members for his school in Japan. He competes for the Japanese-American team during the Raitai Tournament.

His significant participation occurs at the Chinese Challenge Tournament in China, where he confronts Retsu Kaioh. In this fight, Jaku demonstrates considerable combat prowess, disabling Retsu Kaioh's right arm and stunning him with a kick, followed by a damaging headbutt. He possesses a specialized physical trait: his back is seven times harder than his front, enabling him to withstand Retsu Kaioh's attacks without significant injury. Despite these strengths and capabilities, he is ultimately defeated by Retsu Kaioh.

Jaku exhibits above-average intelligence, consistent with his role as an instructor. He maintains an acquaintance with the prominent martial artist Doppo Orochi.