Kagechiyo, Kemumaki's black-furred ninja cat partner and fellow antagonist, hails from the Koga ninja clan. He typically operates under Kemumaki's orders, participating in schemes against Kenichi Mitsuba and Kanzo Hattori. His primary role involves intelligence gathering, often by hiding within the Mitsuba residence to eavesdrop and report.

He wields a signature combat technique: generating static electricity by rubbing a metal plate against his back and discharging it as an attack, though overuse causes temporary weakness. Kagechiyo's loyalty to Kemumaki is sometimes tested, especially when facing punishment for failures or when Kemumaki enforces strict Koga clan rules, like prohibiting ninjutsu for theft. This tension led to his temporary excommunication after stealing ice cream.

Despite his antagonistic role, Kagechiyo occasionally shows reluctance or resentment towards Kemumaki's demands. He sometimes fantasizes about abandoning ninja life to become a pampered house cat, reflecting underlying dissatisfaction. He maintains a persistent rivalry with Hattori's ninja dog, Shishimaru, their encounters often escalating into confrontations. Kagechiyo also harbors a fondness for fish, which occasionally influences his behavior.

His dynamic with Kemumaki shows occasional shifts, including rare moments assisting Hattori's group. Their relationship remains complex, blending obedience with intermittent defiance, particularly when Kagechiyo is scolded for incompetence or subjected to harsh treatment.