Jūzō Kakei serves as a samurai under Yukimura Sanada, bearing the title Brave of Metal. He maintains a serious demeanor and unwavering loyalty towards his master. He reacts visibly with discomfort, annoyance, or jealousy to Isanami's close interactions with Saizō. Despite his combat prowess, he harbors a significant fear of heights.

Physically, he appears as a middle-aged man with black hair, brown eyes, and a distinctive scar on his right cheek. His primary weapon is the customized rapid-firing matchlock gun Saya, which he relies on heavily during missions.

His involvement starts when he guides Saizō and Isanami to Izumo to investigate enemy activities. Ambushed by Yuri Kamanosuke and henchmen, he demonstrates precise marksmanship by shooting all attackers. He later ascends a cliff to rescue Isanami while Saizō confronts Yuri, overcoming his acrophobia. The group proceeds to Izumo Shrine and faces Hattori; Kakei defeats Hattori's assistant. After Isanami's kidnapping by Date forces and subsequent rescue, Yukimura summons the Braves. During this gathering, Kakei encounters Miyoshi and accidentally bends his gun, Saya, causing him considerable distress. Prompted by this incident, he departs specifically to repair Saya.