Koichi Zenigata, a Japanese Interpol inspector, dedicates his career to relentlessly pursuing the master thief Lupin III. Originating from the Tokyo Metropolitan Police Department, he initially targeted Fujiko Mine and her partner before redirecting his focus to Lupin after their fateful New York encounter. Though originally named Heiji Zenigata VII—a nod to his fictional detective ancestor—the bloodline connection faded in favor of the simpler Koichi Zenigata. Zenigata’s persona merges obsessive drive with a paradoxical moral compass. Early portrayals depicted him as ruthless and corrupt, but later iterations softened him into an affable yet single-minded figure. His existence revolves around capturing Lupin, culminating in existential turmoil when believing the thief dead, such as his temporary monastic retreat in *The Fuma Conspiracy*. Beneath his tenacity lies vulnerability: he weeps at Lupin’s kindness or mourns the thief’s supposed demise, revealing hidden emotional depths. Muscular and of average height with a cleft chin, Zenigata’s appearance shifts across adaptations—rugged and square-jawed in *The Castle of Cagliostro*, more youthful in later series—yet he consistently dons trench coats and fedoras. A formidable combatant, he masters judo, karate, and precision marksmanship with a Colt M1911. His signature move, hurling handcuffs with unerring accuracy, echoes his ancestor’s coin-throwing legacy. Though sworn to arrest Lupin, Zenigata oscillates between rivalry and reluctant partnership, joining forces against threats like Count Cagliostro’s counterfeiting ring. Their dynamic thrives on mutual respect: Lupin affectionately calls him “Pops,” while Zenigata begrudgingly admires the thief’s brilliance. Beyond Lupin, Zenigata maintains guarded professionalism with figures like Fujiko Mine, cautiously collaborating despite her criminal ties. Fleeting romantic interests, such as reporter Maria in *Crisis in Tokyo*, pale against his work obsession. A referenced daughter, Toshiko (*The Mystery of Mamo*), remains absent in later narratives, underscoring his solitary existence. Zenigata’s career weaves through promotions and demotions—notably a stint as a beat cop between anime series—yet his Lupin-focused mission overrides institutional allegiance. Clashing with Interpol bureaucracy, his collateral arrests of other criminals preserve his reputation. Rare showcases like *Lupin III vs. Detective Conan* highlight his resilience, surviving severe injuries to resume the chase. Evolving across media, Zenigata balances comedic mishaps with genuine skill. Modern arcs, such as *Part 5*’s amnesia-driven theft persona, refresh his dynamics without eroding core traits: unyielding determination, an unbribable moral code, and an enduring, complex bond with his eternal rival.