Koichi Zenigata

, usually called , is a fictional character created by Monkey Punch for his manga series "Lupin III", which debuted in "Weekly Manga Action" on August 10, 1967. He is named after the famous fictional Japanese detective Zenigata Heiji, whose descendant he is implied to be.
He is the star of the live action Inspector Zenigata TV series and portrayed by Ryohei Suzuki, making it the second Lupin III-based property not to star Lupin as the protagonist.
Creation.
Inspector Zenigata was conceived as Lupin's arch rival to create a "human Tom and Jerry".
Monkey Punch has said that he believes the Lupin III story can never end but that if he had to, both Zenigata and Lupin would have to end as equals. They would either both fail, both win or both get very old.
Personality.
Inspector Zenigata hails from Japan, city of origin unknown. According to "", his original title was Tokyo Police Inspector whose original interest was the capture of Fujiko Mine and her then partner. His pursuit took him to New York where he first met Arsène Lupin III. He left the Japanese Police Force in favor of enlisting in ICPO (Interpol) for the sake of specifically bringing Lupin to justice. For a brief period between the first and second TV series, Zenigata was demoted to a beat cop in an unknown location of Japan. 
Zenigata has made it his life's mission to arrest Lupin. The other members of Lupin's gang are targeted for apprehension as well, but Zenigata usually ignores them when Lupin himself is present. Lupin and Zenigata appear to be the worst of enemies, but in the anime they are, in a manner of speaking, friends; something Lupin shows openly (often by greeting Zenigata with mock affection), but it is an idea Zenigata is extremely reluctant to entertain. Similarly, he is often awed by Lupin's genius. Zenigata has an attachment to Lupin with the belief that no one should kill him or worse, capture him, besides Zenigata himself. Lupin's opinion of Zenigata is a little less caring, but still filled with respect. He often seems amazed that Zenigata can keep up with him. At times he's overwhelmed by how much thought Zenigata has put into his traps for Lupin. In instances where Zenigata has been injured in the field or believed dead, Lupin avenges the Inspector by hunting down his attacker.
While he has some interest in capturing Jigen, Goemon, and Fujiko, he is really after only Lupin, and as such shows little interest in them when Lupin himself is involved. During the course of his hunt for Lupin, Zenigata has revealed and arrested a large number of criminals from all walks of life, sometimes unintentionally and with help from Lupin. This is a major reason why ICPO tolerates his repeated failures to capture Lupin: the "collateral damage" from his lifelong quest has made him a highly rewarded and respected officer of the law.
In "The Mystery of Mamo", it is mentioned that Zenigata has a daughter named Toshiko, but to date this has never been mentioned since the film. In an episode of "Lupin III Part II", Zenigata is asked if he has any family, to which he replies "not yet". He's unable to settle down because of his eternal pursuit, and although he sometimes longs for female company (such as a reporter Maria in "Crisis in Tokyo", who compares him to her father) his single-minded attitude regarding the capture of Lupin leaves no personal time available. In the 2012 series "", Fujiko is seen performing sexual favors to an apparently willing Zenigata in order to avoid jail time. The Pioneer dub of the second anime series inserted Zenigata comically making continuous references to his mother.
Zenigata is a quite sensitive person who often weeps uncontrollably, particularly when Lupin has done him an act of consideration, or when relieved to discover Lupin is OK after assuming his death. In Seven Days Rhapsody, Zenigata captures Lupin in a rough hug after he leaps from a helicopter. He states that they were destined to be together. In the post credits scene, Lupin is standing out in the rain and Zenigata approaches him with eyes wide and kind and says that Lupin will catch cold outside and they should go eat some katsudon together in a warm interrogation room.
On occasions when Lupin appears to be dead, he mourns him more expressively than anyone else; partly from genuine grief, partly because he no longer has a goal in life. In the 1987 OVA "The Fuma Conspiracy", Zenigata actually retires from police work when he believes Lupin has died and becomes a monk, believing that if he prays enough Lupin will be a law-abiding citizen in his next life. Because of this singular ambition, he is never particularly displeased when Lupin manages to escape his custody, since that means the hunt will go on. On one occasion when Zenigata is able to successfully capture Lupin and place him in prison he becomes frustrated that Lupin hasn't yet escaped after a year has passed and wishes for him to escape or be rescued by Jigen. The only time where he hasn't mourned Lupin's "demise" "The Mystery of Mamo", where he is shown to be the only one who doesn't believe Lupin was actually executed, and tries to drive a stake into his body to test if he is really dead, only for the corpse to explode and Lupin to reveal himself as actually alive and well moments later, confirming his suspicions. Towards the end of the movie, he even tells Lupin that as long as there is one Lupin in the world, he'll continue to follow him "straight through the gates of Hell".
Zenigata even goes so far as to cryogenically freeze himself so that he can continue to chase Lupin in the future, though both his and Lupin's cryopods malfunction and they are stuck in the present.
The origin of Zenigata's and Lupin's mutual regard was based early in the series when Lupin had the chance to shoot the Inspector, but instead wished him well and escaped. Since then, an unwritten understanding exists between the pair where neither will attempt to cause the death of the other. Further, the two are best referred as unacknowledged friends; several occasions have occurred where Lupin and gang aided Zenigata out of a life-threatening situation. When a woman the Inspector loved was killed by a criminal gang, Lupin participated in avenging her murder. And when an old enemy of Lupin's shot Zenigata point blank while he helplessly watched, a wild motorcycle chase began to apprehend the killer, partly for Lupin to conclude affairs with the adversary, partly to avenge the (supposed) death of the Inspector.
Physical skills.
Zenigata appears to be in good physical shape for his age; his proficiency in Judo and Karate have been revealed many times, with him able to dispatch multiple attackers with minimal effort. He's also capable with a jitte, the traditional Japanese police weapon designed to counter sword attacks. Other skills include his marksmanship with his weapon of choice, a Colt .45 automatic pistol, and an almost inhuman skill with throwing handcuffs, tossing them in a bola-like manner at his prey.
Zenigata's subconscious appears to be somewhat in control of his body. During chases he can perform outlandish physical feats such as jumping over huge obstacles and beating down a dozen attackers without thinking, simply because of his preoccupation with Lupin. For example, in 1997's "In Memory of the Walther P-38", the mere mention of Lupin's name is enough to wake him from a coma, even as he is about to succumb to a near-fatal bullet wound. When accidentally knocked out by the stun-gun wristwatch used by Conan Edogawa in 2009's "Lupin the 3rd vs Detective Conan", he was only out for a few seconds when according to Conan, it would render an elephant unconscious for 30 minutes. Zenigata's obsession when he gets upset or close to Lupin seems to give him abilities beyond the normal. Many are the heavy locked doors he manages to crash through when fury overtakes him. 
The Inspector's appearance has stayed consistent through both the manga and anime series; around 6 feet, Pops has a somewhat long face ending in a bulky chin. Much like Lupin, he has extended sideburns that reach to the lower part of his cheeks. Dressed modestly in a brown business suit with white shirt and brown trench coat, he as well wears a standard flat-brim fedora. He occasionally smokes and drinks. His preferred cigarette is the Japanese made Shinsei, and enjoys hard liquor of various designs, usually bourbon or sake. He eats large quantities of food when time enables, which in no way affects his body shape as his on-the-move lifestyle keeps him from gaining weight. 
Zenigata is usually presented in the anime as clumsy and drawing hasty conclusions, but equally he is depicted with extremely efficient detective skills. 
As a first class manhunter, Lupin's upcoming capers are usually predicted by Zenigata based on his prey's behavior, habits, and information about Lupin's research.
Although 99 times out of 100 Lupin and gang escapes the Inspector's grasp, they are still astonished at his physical adroitness and capability of staying on their tail.
Nicknames.
Lupin often refers to Zenigata as "tottsan" (とっつぁん), a form of address that is usually translated as "Old Man" or "Pops", with "Pops" being used most frequently in the English dub. Other translations have the used the terms "daddy", "daddy-o", and "papa". He is named after a famous fictional Japanese detective, Zenigata Heiji. Zenigata's ability to handcuff criminals at a distance also comes from Zenigata Heiji, who threw coins with great force and accuracy and used them as weapons to disable criminals. In Japanese, the title of inspector is "keibu" (警部), although an early dub of "Castle of Cagliostro" erroneously stated Keibu as Zenigata's first name. In the Filipino dub of the series, Lupin refers to Zenigata as "depektib", a play on the words "detective" and "defective".
Actors.
Inspector Zenigata was first voiced by Shinsuke Chikaishi in the CinemaScope version of the 1969 , while Chikao Ōtsuka voiced him in the pilot's TV version. However, Gorō Naya was given the role when the first anime was actually produced (1971–72) and he continued to voice the character until 2010, with one exception. Due to budget concerns, TMS decided not to employ the regular voice cast for the 1987 original video animation "The Fuma Conspiracy", with Zenigata voiced by Seizō Katō. The 2011 TV special "Blood Seal - Eternal Mermaid" marked the first appearance of Kōichi Yamadera as the character and he continues to voice Inspector Zenigata to this day. Naya did return to the role once more for the 2012 "Lupin Family Lineup" short original video animation.
Greg Starr voiced Inspector Zenigata in the 1979 Toho English dub of "The Mystery of Mamo", where his name was changed to "Detective Ed Scott". David Povall (1992-5, Streamline). Marc Matney (1995, AnimEigo). Seán Barrett (1996, Manga UK). Kevin Seymour (2000, Animaze/Manga). Phillip Wilburn voiced the character for Funimation Entertainment's dubs of several TV specials and theatrical films between 2002 and 2005. Dan Lorge voiced Zenigata in the Phuuz dub for Pioneer/Geneon's release of the second anime between 2003 and 2006. Richard Epcar was given the role for Funimation's 2013 dub of "The Woman Called Fujiko Mine", and reprises the role in the Bang Zoom! Entertainment dub for Discotek Media's 2015 release of the "" film. In 2017, Doug Erholtz took over the role for Discotek's dubs of the fifth and sixth anime.
Tadanobu Asano starred as Zenigata in the 2014 live action film "Lupin the 3rd".
Japan's NTV broadcast network featured a live action Inspector Zenigata TV special and subsequent series with Ryohei Suzuki, ("Hentai Karmen", "Gatchaman" both 2013) starring as the Inspector. The show follows the character as a brilliant, doggedly capable IPCO officer successfully chasing down an assortment of criminals. Joining Suzuki are Atsuko Maeda and Takahiro Miura as the Inspector's neophyte detective aides. The series and special both were presented on Hulu Japan in February 2017. It revealed the first poster visual on January 16, 2017.
Reception.
Zenigata was voted the eighth best supporting character in anime by Mania.com. Mania.com also put Zenigata as the 9th greatest anime detective.
Mike Crandoll of Anime News Network compared Zenigata's pursuit of Lupin to Wile E. Coyote.