Kaori Makimura, adoptive sister of former detective Hideyuki Makimura and later partner to Ryo Saeba, steps into her brother’s role after his death, coordinating clients and missions with tactical precision. Born Kaori Hisaishi, her adoption into the Makimura family followed her biological parents’ demise, a past that fuels her protective drive toward the vulnerable. Her fiery temperament manifests in wielding a mallet against Ryo’s habitual flirtations, a humorous counterpoint to their high-stakes work. Though her marksmanship and combat skills initially suffer from Ryo’s deliberate firearm tampering—a ploy to shield her—she hones her abilities, transitioning from logistical support to active fieldwork. Their partnership simmers with unspoken affection: Kaori masks growing feelings under exasperation at Ryo’s womanizing, while he silently upholds a vow to her brother to avoid entanglement. Narrative threads suggest mutual recognition of their bond, with the manga’s closing arcs alluding to potential matrimony. Her wartime orphanage roots and adoptive history sharpen her pragmatism, balancing compassion with ruthless prioritization of client safety over profit. In missions like the *Shinjuku Private Eyes* conspiracy, she deciphers threats with strategic acumen, adapting to technological hazards without losing her core resolve. Evolving from reactive ally to Ryo’s equal, her journey navigates vigilante ethics and the push-pull of duty versus personal yearning, cementing her as indispensable to their shared legacy.