Originally a member of the Gorma Tribe, Chief Officer Jia Xu (嘉挧参謀長,Kaku Sanbōchō), he formed the Dairangers to oppose the Gorma in the present day under the human alias of Master Kaku (道士嘉挧,Dōshi Kaku). He is one of the earliest people to be aware of Kou's true identity as KibaRanger. But when Daijinryuu appeared, he returned to the Gorma in his metallic red Cyclops-like armor. Jiaxu hoped he could stop the fight as the 16th Gorma Emperor to end the war, using the Tower of You Power and the Tower of Qi Power as boosters to battle Shadam for the right to the throne. But once Gara and Zydos destroyed them, Jiaxu lost against Shadam, mortally wounded, and died in the arms of the Dairangers. He later appeared in spirit to the Dairangers, telling them the Gorma must be thwarted without being destroyed.
Kaku's name come from Jia Xu 嘉挧 (,Kaku), an advisor to the warlord Cao Cao in the late Eastern Han Dynasty that served as an official in the state of Cao Wei under Cao Pi, Cao Cao's son and successor during the Three Kingdoms era.
His name could also be translated to Master Crane, and the crane is coincidentally the animal motif of the leader of the succeeding Sentai, the Kakurangers.
Although Master hasn't had a Power Rangers counterpart, in "Quest for Power", the five-part episode of the second season of VR Troopers, there was a brief appearance of a prison guard that seemly resembled Chief Officer Jia Xu.
In addition, the armor parts and boots from the final armored form of Master Kaku were later repainted silver and combined with a horned helmet-engraved head, a generic body, the right arm Kamaitachi's enlarged form, and the necklace of Gnarly Gnome to form Plague Patrol #2.