Nicky Larson, originally named Ryo Saeba, operates as a private detective and "sweeper" in Shinjuku, Tokyo. Surviving a Central American plane crash at age three led to his upbringing as a guerrilla fighter, erasing his prior identity. This forged extensive combat skills, weapons mastery, and rare survival of exposure to Angel Dust. Post-conflict, he moved to the United States before settling in Tokyo, co-founding the "City Hunter" agency with Hideyuki Makimura. After Hideyuki's murder, Hideyuki's sister Kaori Makimura became his partner, managing clients and frequently restraining his overt lechery with a giant mallet. He accepts cases via the coded message "XYZ" left on a Shinjuku Station board, undertaking bodyguard assignments, investigations, and underworld confrontations. Despite a comedic obsession with attractive women—marked by exaggerated "mokkori" reactions—he transforms into a hyper-competent professional during missions. His capabilities include unmatched marksmanship (notably the "one-hole shot"), mastery of hand-to-hand combat, strategic demolition, and evasive driving, often employing a Mini Cooper. He wields a Colt Python .357 Magnum and maintains a "Crazy-Prepared" approach, concealing backup weapons, explosives, and sedatives within his clothing. Key relationships define his dynamics: Kaori acts as his emotional anchor and frequent combat partner, their unresolved romantic tension persisting throughout media. Umibozu (Hayato Ijuin), a former Central American adversary, evolves into a trusted sweeper ally. Police detective Saeko Nogami leverages his attraction for investigative aid but consistently breaks implied romantic promises. Protecting Ai Shindo in the 2019 film *Shinjuku Private Eyes*, he unravels a citywide conspiracy linked to her scientist father's suspicious death. His portrayal retains core traits: comedic pursuit of women, unwavering client protectiveness, and tactical brilliance. The film integrates classic elements like Kaori's mallet and his "one-hole shot." The 2018 French adaptation *Nicky Larson et le parfum de Cupidon* mirrors these characteristics, depicting him as a perverted yet elite protector safeguarding "Cupid's Perfume." It replicates iconic scenes including Laura (Kaori's counterpart) wielding her mallet and the "thought bird" visual gag, introducing no new backstory. His core traits—professional excellence, comedic lechery, and moral steadfastness—remain consistent across official media, without substantive development. Spin-offs like *Angel Heart* inhabit separate continuities and do not contribute to his canonical progression.