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2018 anime art
Japanese ねずみ男
English Ratman
Species Half-Yōkai
Gender Male
Age Over 300
Height 160cm
Weight 49kg
Abilities Bad breath
Flatulence attack
Affiliation Whoever pays him the most
Kitarō Family
Other Information
Likes Money
The occult
Dislikes Good deeds
Degree Lazy Studies, Bizarre University, Filth Department
Last Bathed? Long before you were born, kid
Pride Ridiculously high
Pride (when in danger) Nonexistent
First Appearance
Manga The Boarding House (1960)
Anime Episode 1 (1968 anime)
see Cast
[v · t · e]

Nezumi-Otoko (ねずみ男, "Rat Man") is a rodent-like half-yōkai and member of the Kitarō Family. He is Kitarō's self-proclaimed best friend and a notorious trickster. Born to a human and a yōkai, he constantly tries to con members of both races, but almost always gets his comeuppance.

Like Medama-Oyaji, he is an original character created by Shigeru Mizuki.

His nickname is BiBiBi no Nezumi-Otoko (ビビビのねずみ男). The phrase BiBiBi derives from the sound effect binta (slap in the face), but in the 5th anime it is implied to come from the sound Nezumi-Otoko makes as his whiskers tremble whenever he comes across a possible money-making scheme.


Nezumi-Otoko (by Shigeru Mizuki)



Nezumi-Otoko looks human except he has whiskers and buck teeth. He wears a long brownish cloak which fits him pretty well. He has a small patch of hair on the tip of his head. Underneath his robe he wears a loincloth and his skin is covered with ringworms and scabs.

Early on, his face was a little different and his head was shorter, protruding forward. His bangs stuck out from underneath his hood.


Nezumi-Otoko is Kitarō's troublesome and loathsome friend. He is the filthiest man in Japan and claims to have never bathed once in his life, although he has actually been seen bathing a number of times. Because of this, his body is covered with ringworms and welts. His breath is quite foul, and it is said he can drop a fly from 10 meters away with one breath. He is a self-proclaimed graduate of the Bizarre University's Filthy Department and a lover of the occult. He boasts of receiving a doctorate in "Lazy Studies," but whether any of this is true is never made clear. He has also claimed that he actually attended the same Yōkai Academy as Kitarō.


While it is assumed he was born of a human and a yōkai, he has been depicted living on an island inhabited only by rats, implying his parents may be a human and a rat.

In GeGeGe no Kitarō: Jigoku Hen, he gets lost between the human world and the spirit world and ends up discovering a "Nezumi-Otoko World". It is revealed that "Nezumi-Otoko" is merely a general term used for his kind in this world, and that his real name is "Peke Peke Nezumi" (根頭見ペケペケ , Nezumi Peke Peke). In the manga he also meets his mother here, though in the anime she turns out to be Nurarihyon's minion Sasori-Onna in disguise. Whether these facts apply to the main story is unknown.

First Appearance

He first appeared in the Hakaba Kitarō rental manga in the story "The Boarding House." Originally depicted as Dracula IV's minion, while searching for a new home for his master he came across the boarding house run by Yasha and the possessed Kitarō. At that same time, he also found an unconscious Medama-Oyaji, cooked him in tempura, and fed him to his master. Since then he has found himself opposing Kitarō and Medama-Oyaji many times, usually quickly giving up after feeling Kitarō's Spirit Lightning.

In the remake Odoro-Odoro vs. Vampire, he disappears long before the end of the story.

Nezumi-Otoko's first meeting with Kitarō and Medama Oyaji has been depicted the 2 following ways:

  • In "An Odd Fellow," right after Medama Oyaji gives Kitarō the chanchanko, Nezumi-Otoko suddenly appears and claims to be a celebrity in the occult world who is always training his knowledge. In the anime version this scene occurs in Episode 2 before they meet at the boarding house. In the manga, Kitarō and Medama-Oyaji believe his claims, while in the anime they don't.
  • In Novel GeGeGe no Kitarō, he first appears in The Birth of Kitarō right after Kitarō leaves home. He steals a fish from Neko-Musume and runs away, establishing that he already knows her and Sunakake-Babaa before meeting Kitarō.


Nezumi-Otoko is basically useless in battle, but through his wits can often get a surprise attack with one of his disgusting techniques.

He is usually flat broke without a home or any possessions other than his clothes, but he often hatches money-making schemes, carrying around special props and "BiBiBi no Nezumi-Otoko" business cards. He is extremely hard headed, often trying to continue his schemes (or try a new one) even after he has been caught. He knows how to drive and owns an old Rolls-Royce style hearse. In the 5th anime he instead has a regular antique car, a gift from Hakusanbō. He has no trouble learning how to use modern devices such as cell phones or laptops, and even Kitarō and Medama-Oyaji find this skill of his impressive.

He comes up with a number of different jobs during schemes, most frequently are the likes of "yōkai researcher", "detective" or "bodyguard". He will often sell himself as Kitarō's agent or even Kitarō himself on some occasions.

For a time, he worked with Shinigami helping people with assisted suicide, a job he says warmed his evil heart. In his solo appearances, he has played various different roles, such as a ninja, a hermit, an alchemist, a shrine God, a politician and a loincloth salesman.


Nezumi-Otoko is frivolous and easily swayed by money, and as such villains have no trouble convincing him to betray Kitarō with the promise of money or simple flattery. He is a troublemaker who often causes serious problems, having released sealed youkai out of his interest in the occult, cut off Kitarō's arm and shoved him into a hole, conspired with Shinigami to poison Kitarō, among other nasty deeds. But, Kitarō almost always lets him off the hook with just some minor scolding. Also, whenever Kitarō gains an advantage over a foe, Nezumi-Otoko always instantly runs back to his side. In the anime versions he is considerably less evil, particularly in the 3rd series where he constantly cooperates with Kitarō in order to win favor in the eyes of Yumeko. Early on in the 1st series he is depicted as truly being Kitarō's friend, such as in Episode 10 when he is captured by the Western Yōkai Corps, and refuses to betray Kitarō even though they threaten him (he does so anyway, but only under Backbeard's hypnosis). However, as the 1st series went on, he started to become more eager to betray Kitarō for money.

His constant need to annoy and trouble people seems to stem from the years of ill-treatment he received from humans and yōkai alike for being a half-breed before he ever met Kitarō and Medama Oyaji. He does not appear to have any family (although his little sister Nezumi-Onna (Rat Woman) appears in Mizuki's short story "The Fantastic Notebook"), but when he meets his long-lost little brother (see Oritatami-Nyūdō) he is willing to pay Kitarō the money he stole and in the 4th anime even takes up an honest job to support the two of them. In the end however, his little brother turned out to be a mujina in disguise). He was also easily deceived by Shinigami into thinking he was his older brother and helped him with his schemes, indicating that deep down inside Nezumi-Otoko is just lonely for a family.

Naturally, he is not well trusted by his fellow yōkai, and yet festivals never seem to get too lively unless Nezumi-Otoko is there. He is a moodmaker and likes to help arrange the festivals. At games and tournaments such as the Yōkai Rally and the Jigoku Marathon he often volunteers to be commentator or concession salesman. When his soul is stolen by Ōkubi and Hone-Onna (in episode #26 of the 2 anime), a funeral service is held for him at Konaki-Jijii's house, and although they call him a fool during the service they are all grieving, particularly Neko-Musume who runs away crying. On the other hand, when Yasha steals his soul (episode #3 of the 4th anime), while Neko-Musume is sad the other yōkai makes harsh statements like "I'm not sad he's dead" and "I won't be happy if he's revived."

He is easily and repeatedly smitten by women, first falling in love with Gama-Reijō in the rental manga story "In the Face of the Enemy." Also, other than Gama-Reijō and Hone-Onna (in the 5th anime) he is usually only attracted to beautiful women, calling himself an "ally to all beautiful women". However, because he is so filthy and weathered women usually dislike him and run to Kitarō's side at the sight of him. Occasionally woman will appear to be interested in Nezumi-Otoko (this particularly happens a lot in the 5th anime), but this is usually a trick by the villain of the week to get Nezumi-Otoko to betray Kitarō. Only rarely has there been situations where it is a mutual love, but these stories usually only last a single episode and with both of them sad.

Relationship with the Kitarō Family

Nezumi-Otoko and Kitarō share a close but rocky bond and can't seem to be rid of one another. According to Konaki-Jijii, the two of them used to often go for a drive around the country in Nezumi-Otoko's car. His only other close relationship is with Hakusanbō, whom he has known for quite a long time (he once told Hakusanbō that his stage show has used the same acts for hundreds of years).

As a means to earn money, Nezumi-Otoko will claim to work for Kitarō and try to con victims out of money by demanding a Yōkai Extermination fee. Whenever Kitarō learns of this, he makes Nezumi-Otoko refund everyone's money. He is also not above straight up stealing from people's houses, though he usually gets his comeuppance for this from Neko-Musume.

He doesn't get along with cats and cat-like yōkai, particularly Neko-Musume, whom he considers his natural enemy. In the story Mammoth Flower (4th anime version), when he is at death's door due to the effects of turning into the Mammoth Flower, he tells Kitarō his one regret is he never got to smack Neko-Musume on the head.


Nezumi-Otoko is well known for and seems to prefer to be filthy, although he doesn't mind using the occasional hot spring. His body is riddled with ringworms, welts, and scabies, and he constantly scratches himself. This skin disease doesn't appear to be one that exists in medical records, and it is believed it is a disease only Nezumi-Otoko has. He has bad breath and farts a lot, and he can use his filthy clothes as a weapon (see Techniques). In "The Two Tanukis" when he is captured in the tanuki's trap, he attempts seppuku only to have a swarm of large tapeworms crawl put of his stomach.

Being a Half-Yōkai seems to merely give him a long life span, since other than the above mentioned stench techniques (which are stronger than normal because of his yōkai powers) and his rat-like features, he has almost no special powers. He does have some yōkai vitality, as he is able to open seals a normal human could not and survive punishment from other yōkai, though this seems to be the limit of his strength. However, he is a genius when it comes to his words, and there are many times when he is able to deceive and/or talk his way out of trouble with Kitarō and enemy yōkai, but he pretty much only uses these skills for his money-making schemes. However, he is usually exposed by Kitarō or thwarted by other yōkai, and whether by returning the money or by having it stolen he always ends up poor again. He also has a rat-like life force, and every time he is eaten or absorbed by a yōkai he manages to somehow return safely. Also, in the rental manga chapter "A Foolish Man," a blood-transfusion from him is able to make a dying old man young again.

For the same reason, he loves to eat human food, although his favorite food is slugs. He often eats caterpillar tempura and frogs and will rummage through people's trash cans for food. He also likes to eat cockroaches, saying that he loves the crunching sound they make. But when it comes to water he prefers clean river water, saying that "it tastes good, unlike that piss-filled city water." He can also eat rotten food like it's nothing, and years of doing so has given his digestive system sterilization powers.


  • Bad Breath - Because of a diet of toads and crickets and never brushing his teeth, he can breath out a particularly foul breath attack. It is so pungent that he can drop a fly from 10 meters away and knock out nearby humans. In The Yōkai Cloth he was able to knock out all the humans being controlled by Chi, prompting Ido-Sennin to remark that his breath is more effective than tear gas.
  • Farting - Probably Nezumi-Otoko's strongest attack. Like with his bad breath, it is so foul smelling that he can knock out anyone who smells it or make their eyes water. He farts with enough force to launch himself like a rocket, making it powerful enough to even give people a heart attack. It can be hazardous and even lethal for humans and can immobilize even the strongest yōkai that crosses him, even the likes of Kitarō, Elite, Yadōkai and Kagami-Jijii. Even the legendary Count Dracula faltered a bit after smelling it. He has even been able to use his farts to escape from Nurarihyon.
Because of the pressure and the concentration of methane gas, if he lights his farts they can become useful firepower. Because the gas is so powerful, Nezumi-Otoko claims no living thing can survive being inside his digestive tract (An Odd Fellow). However, Medama-Oyaji has been able to survive being swallowed by him by escaping out of his anus (The Yōkai Army, Yōkai Colosseum), and in The Two Tanukis it is revealed a large number of parasites live inside of his intestine.
According to Nezumi-Otoko, he can make his farts stronger by holding them in for long periods of time. By eating old and rotten food, he can build up gas in his stomach. He says he will only eat food up to three years old, though he did eat 100 year old food in order to defeat Yadōkai (5th series, Ep. 52).
  • Fart Ring
  • Teeth - Nezumi-Otoko's buck-teeth are strong and sturdy. He can chew through walls (Johnny in the Mist) and ropes. In GeGeGe no Kitarō: Sennen Noroi Uta he even chews up a rock door. Medama-Oyaji has compared his teeth to a saw. It is unknown if his diet and lifestyle made his teeth this strong or if he was born this way.
  • Slapping
  • Punching
  • Clothes
  • Skin Flakes
  • Catnip
  • Parasites
  • Spirit World Phone
  • Yōkai Energy
  • Invisibility
  • Spittoon Hell

Mizuki on Nezumi-Otoko

In the anime he is a regular character from the beginning, first appearing in Episode 2: Yasha of the 1st series. The despicable Nezumi-Otoko was Shigeru Mizuki's own favorite character, and as such appeared in many of his other non-Kitarō stories. In interviews, Mizuki usually answered questions regarding his favorite character immediately with "Nezumi-Otoko", and also mentioned that he didn't have any other favorites out of the Kitarō Family or his other yōkai characters.

Regarding Nezumi-Otoko's role in the story, Mizuki has said "Kitarō is a fool. Because he is an ally of justice, because he is like Superman [...] he never has thoughts along the lines of money meaning happiness. Because of this, if Nezumi-Otoko doesn't appear, the stories won't unfold steadily."

Originally Mizuki didn't want to write about an ally of justice type hero, at first he wanted Kitarō to have a strong hint of social satire. But at the request of his editors, Mizuki went against his own vision and gradually changed the series into a hero manga with super powers and more yōkai battles. So Mizuki decided to increase Nezumi-Otoko's appearances and have him constantly criticize the other characters as a way to express his own viewpoint. During the Shukan Jitsuwa run, there were also stories that focused entirely on Nezumi-Otoko, with Kitarō and Medama Oyaji only appearing for a couple of scenes or not at all.

Anime Versions

Nezumi-Otoko 1968


Nezumi-Otoko 1971


Just like in the original manga, Nezumi-Otoko is always cooking up dishonest money-making schemes. In those days it was common to see him at Kitarō's house, either reading the newspaper or bumming a meal. Also like in the manga, he often joined Kitarō on his investigations. He has a tendency to call himself a Yōkai Researcher and use pretexts such as his research to carry out money making schemes. Whenever a good opportunity arises he is sure to frequently drop Kitarō's name, calling himself both Kitarō's best friend and manager or even claiming to be Kitarō himself. But, whenever he finds himself in danger he has no trouble abandoning Kitarō, and like the original manga Kitarō will always inevitably forgive him. He will also frequently try to sway Kitarō with a cut of his profits. Therefore Medama Oyaji will almost always speak harshly to him, and Kitarō on several occasions has gotten fed up with him and declared "I'm through with you." Likewise, Nezumi-Otoko has said the same thing a few times after Kitarō hindered some of his schemes. Because the 1st series was in black & white, it is unknown what color his robe was, but in the 2nd series it is colored gray (instead of light brown, like in the original manga).

Whenever he is caught by Kitarō he begins talking in an effeminate manner (known as Onee-Kotoba). This was a special characteristic performed by his original voice actor Chikao Ōtsuka, and he also does this when he reprized the role for the later series Hakaba Kitarō.

Nezumi-Otoko 1985


The 3rd series saw the development of a fairly different Nezumi-Otoko. As Kitarō was depicted as a much stronger "hero of justice," his punishments for Nezumi-Otoko were much harsher. He also falls in love with Yumeko Tendo and as such is willing to do anything to be around her, even follow Kitarō on dangerous investigations. He does anything to win her favor, but usually just ends up annoying her. Unlike in the first two series, he is shown living in apartments and tents and will also work at shops and offices to make money. There are also several times where he is shown wearing work uniforms and western-style suits. He dislikes baths and considers even boiling the water for a bath to be too much work, but he is seen enjoying a dip in the hot springs many times. Also, his voice actor Kei Tomiyama would ad lib dialogue several times, which was uncommon for him.

Caroline's death

Nezumi-Otoko crying over Caroline

In the 4th movie, he is featured as a second protagonist alongside Kitarō. He falls in love with a young girl named Caroline whom he meets and protects on a streetcar that is attacked by a yōkai. The two have mutual feelings for one another, and Nezumi-Otoko is even uncharacteristically willing to risk his life for her. However, he soon learns that she is actually the daughter of Yōkai Prime Minister Guwagoze, a minion of [[[Nurarihyon|the Yōkai Emperor]]. Although heartbroken he eventually forgives her, and soon after helps her and Kitarō obtain the tears of Oboru-Guruma. However, Caroline is killed by Oboru-Guruma, and with her dying breath says "If I had been born a yōkai, I would've become Nezumi-Otoko-chan's bride." Nezumi-Otoko screams and cries and becomes furious with the Youkai Emperor. Guwagoze as well is tremendously saddened that he was never able to gain his daughter's forgiveness. After Kitarō defeats Oboru-Guruma and prevents the bombing of the Japanese Diet Building, Nezumi-Otoko makes a grave for Caroline and her father, whom had been killed by the Yōkai Emperor, and prays that they be able to get along now.

He is tone-deaf, and as such music-based spells have no effect on him. His robe color this time was a grayish-blue.

Nezumi-Otoko 1996


Performed this time by Shigeru Chiba, who is well-knowm for his high-strung style and ad-libbing, the most frivolous Nezumi-Otoko so far is introduced. He performs his usual money-making schemes, but this time, to fit Chiba's style, many of his schemes involve him speaking and acting like a hawker. After the 1997 bubble collapse, he was shown many times working part time jobs just to earn money for food. Almost every time he is the main focus of an episode, he for some reason or another becomes emotional. He is not usually with Kitarō for his investigations, and if he is already at the scene he is usually taking advantage of things and trying to make money by name-dropping Kitarō. And, as usual, he will also work with the enemy sometimes. He doesn't usually learn a lesson and is often proud of his deeds, and when he tries to scold others for their involvement in the situation, he will anger Neko-Musume and get attacked by her. Also, whenever he refuses to help Kitarō's investigations, Neko-Musume will sometimes pull on his whiskers until he cries. He is a huge fan of the idol singer Chisato Watanabe. Beginning with episodes 6 and 11, he is depicted a few times cross-dressing (as bus guides, shrine maidens, geisha, etc) for his schemes.

From here on, his robe is yellow like in the original manga.



In contrast to Chiba's manic performance, the 5th anime Nezumi-Otoko was much more like in the first series. However, because the sidekick role went to Neko-Musume this time around, there are many episodes in which he has little to do with the plot and sometimes even only appeared in one scene. He commits considerably fewer schemes than in past adaptations, and in fact has been shown to have better morals than before, such as when he helped Nurikabe raise money for his home and when he refused to testify against Kitarō in the The Great Yōkai Trial (whereas in most adaptations of the latter story he is paid by Momon-Jii to lie on the stand). He is also willing to assist and save Kitarō without demanding compensation. When he does work with the enemies, he is a lot better at tricking the others than before. Unlike other adaptations, the fact that he is a half-yōkai is rarely explored and he does not appear to have his chronic skin disease. He is shown to receive instructions as Kitarō's right-hand man from Neko-Musume and Enma-Daiō.

His voice actor, Wataru Takagi, had appeared in the previous series as the Mujina who claimed to be Nezumi-Otoko's long-lost brother.

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In the 6th series, his robe is once again gray like in the 3rd series. Similar to Ōtsuka's performance, he speaks like an Edokko.


As one of the three main characters, Nezumi-Otoko is featured in several other media and on merchandise. As mentioned above (see Mizuki on Nezumi-Otoko), he was Shigeru Mizuki's favorite character and appears in many of his non-Kitarō stories. Many of these stories were collected in a special manga collection entitled "Nezumi-Otoko no Bouken" (ねずみ男の冒険, The Adventures of Nezumi-Otoko). The official website for the 1968 anime DVD collection includes a list of the "3 Best Nezumi-Otoko Schemes" episodes.

He has 3 statues at Shigeru Mizuki Road, more than any character other than Kitarō and Medama-Oyaji, as well as one outside of Shigeru Mizuki Museum of him, Kitarō, and Mizuki himself sitting at a desk. The Kitarō-themed Yonago Station is nicknamed the Nezumi-Otoko Station and features a train covered in pictures of him (although, other trains at the station feature Kitarō, Neko-Musume, and group pictures as well).

In the opening animation for the 1985 anime, Nezumi-Otoko is depicted as the lead singer of a yōkai band with the other members of the Kitarō Family performing the famous opening theme (however, the song itself is performed by Yoshi Ikuzō rather than Nezumi-Otoko's voice actor Kei Tomiyama). In addition, despite his reduced role in the 2007 anime, he is referenced in The 50 Kaitens' version of the opening theme when the lead singer screams "Oh, here comes Nezumi-Otoko!" right before the instrumental break.

Image Songs




  • In the 2002 Kodansha International Bilingual Comics edition, he is referred to as Ratman.
  • In the 2007 anime, he and Neko-Musume were chosen to help Kitaro find the other 47 Yōkai Warriors.
  • Nezumi Otoko narrates Mizuki's Showa historical manga series.
  • Nezumi-Otoko cannot swim.
  • Nezumi-Otoko's favorite book is The Theory of Poverty.
  • According to the 80's anime, Nezumi Otoko is severely tone deaf.
  • Nezumi Otoko has been known to seek medical advice from veterinarians rather then a medical doctor.
  • Nezumi Otoko makes a cameo as a French solider in Mizuki's Hitler manga.
v  d  e
Kitarō Family
See also
47 Yōkai Warriors