Ryo Saeba operates as a sweeper and private detective, renowned for his combat expertise, sharp intellect, and unwavering dedication to justice. Orphaned early, he survived a plane crash in Central America at three years old, later raised by guerrilla fighters in a conflict-ridden region. His Japanese mentor, Shin Kaibara, bestowed the name "Ryo Saeba" during this turbulent upbringing. Forced to consume the drug Angel Dust as a child, Ryo gained enhanced physical and mental capabilities, though the trauma of war left lasting scars, including aerophobia and a deep-seated fear of aircraft. Launching his career as a U.S. mercenary, he collaborated with allies like Mick Angel and Kenny Field before relocating to Tokyo. There, he co-founded the City Hunter agency with former police detective Hideyuki Makimura. After Hideyuki’s murder, Ryo assumed guardianship of his partner’s sister, Kaori Makimura, who evolved into both his fiery-tempered colleague and reluctant confidante. Their partnership oscillates between comedic clashes—often punctuated by Kaori’s oversized hammer—and a layered reliance, underscored by unspoken romantic undercurrents. Beneath Ryo’s womanizing bravado lies a protective instinct and occasional vulnerability, revealing emotions he avoids confronting. A master marksman, Ryo wields the Colt Python.357 Magnum with lethal precision, capable of firing multiple rounds into a single bullet hole. Proficient in hand-to-hand combat, tactical strategy, and high-speed vehicular maneuvers, he shifts seamlessly between a flirtatious facade and ruthless professionalism. His moral code forbids harming innocents or allowing others to compromise their integrity, often steering clients away from his mission’s grim realities through calculated subterfuge. The spin-off Angel Heart reimagines Ryo’s life after Kaori’s accidental death, focusing on his paternal bond with Xiang Ying, a girl who received Kaori’s transplanted heart. This narrative highlights his guilt and capacity for tenderness, contrasting his usual swagger. Alliances with figures like Umibozu—a rival-turned-ally—and Saeko Nogami, a detective exploiting his affections for police favors, further illustrate his loyalty and ethical nuance. Shaped by his childhood in warfare, Ryo fiercely opposes exploiting the vulnerable, particularly women and children. His aversion to air travel and recurring themes of loss reflect buried trauma, masked by humor and bravado. The manga’s conclusion subtly implies a future with Kaori, hinting at emotional maturation, while later adaptations like Shinjuku Private Eyes reaffirm his steadfast pursuit of justice and grudging acceptance of deeper human connections.