Inspector Koichi Zenigata, a dedicated Interpol officer, relentlessly pursues the master thief Lupin III across international borders. He leverages his authority to coordinate global law enforcement in tracking Lupin's activities. Zenigata's personality combines intense focus with moments of emotional vulnerability. His obsession drives impulsive actions, yet he holds underlying respect for Lupin, actively preventing others from harming or falsely incriminating him. This dynamic has even led to reluctant cooperation, such as a time-travel incident stranding them in 16th-century Japan where they united against a common threat involving a time machine and a vendetta targeting Lupin. Despite his professional demeanor, Zenigata openly weeps at unexpected acts of kindness from Lupin or when believing Lupin has died. Physically, he appears as a middle-aged Japanese man consistently wearing a trench coat and fedora. His skills include judo, karate, marksmanship with a Colt M1911 pistol, and an unconventional ability to throw handcuffs with bola-like precision to immobilize targets. Driven by his Lupin fixation, his physical capabilities sometimes surpass normal limits during chases. Zenigata's career spans multiple agencies. Starting as a Tokyo Metropolitan Police inspector focused on Fujiko Mine, his path crossed with Lupin during a New York investigation, prompting his transfer to Interpol solely dedicated to Lupin's capture. This dedication occasionally strains relationships with superiors due to his unorthodox methods and perceived fixation. His personal life remains largely unexplored, consumed by his professional pursuits. His character evolved significantly from early, more ruthless portrayals where he employed lethal force and accepted bribes. Over time, he softened into a principled, albeit eccentric, officer with a steadfast moral code, rejecting bribes and showing genuine concern for justice beyond capturing Lupin. He demonstrates insubordination when confronting institutional corruption or unethical orders, even resigning once to pursue Lupin independently after being commanded to stand down. While primarily focused on Lupin, Zenigata acknowledges Daisuke Jigen, Goemon Ishikawa XIII, and Fujiko Mine as secondary targets. Fujiko occasionally exploits their dynamic through negotiation or manipulation to evade arrest. Spin-off media expands his role, including a live-action series where he investigates cases involving multiple Lupin impersonators, showcasing his deductive skills independently. The character draws foundational inspiration from the historical Japanese detective Zenigata Heiji, with his handcuff-throwing technique serving as a modern homage to his ancestor's coin-based weaponry. This lineage was more explicitly referenced in early iterations before being downplayed.