Yukio Okumura (奥村 雪男 Okumura Yukio) is Rin's younger, fraternal twin brother. A straight arrow and kind-hearted by nature, he is the youngest person to ever pass the Exorcist qualification exam, attaining a Meister in Doctor and Dragoon, and later becomes a teacher at True Cross Academy, where he ironically ends up teaching his older brother in the ways of the Exorcist.
Yukio has teal eyes and dark brown hair. His most notable trait is two moles under his left eye and another one under his mouth. In the anime, Yukio is seen with a mysterious black mark on the underside of his left arm that is now starting to spread throughout his body. This may have something to do with his original birthright as Satan's son and the Demonic powers he was supposed to have shared with Rin as Yukio was shown performing his daily testing and it reacted, but the mark was never fully explained in the anime (though Shura appeared to be alarmed by the sight of it).
As of the last episode, Yukio's mark has spread all the way down past his elbow.
In the anime, since awakening his Demonic powers in episode 22, Yukio now possesses the same Demonic features as his brother, Rin, when in their human form (e.g. the slightly pointed ears and sharper canines). When in his Demon form, he too has a blue flame, elf-like ears, and fangs.
Although they are twins, Yukio is frequently noted to be the exact opposite of Rin, and Ryuji even states that he finds it hard to believe that they're related. Yukio is mostly seen as quiet and calm but often has mood swings. He is usually seen happily smiling, but can easily get sidetracked due to Rin's personality clash, and becomes rather dark. He takes things seriously, but he knows a joke when he hears one.
Although he and Rin get along, for the most part, Yukio is usually quite standoffish and aloof towards his brother, finding him annoying and often scolding him for not thinking things through. He also has a secret resentment towards Rin, not only because he's a demon and the son of Satan, but also because he feels Rin is the one responsible for their adoptive father's death.
On a few occasions, he is shown to have a very aggressive side, though he is very good at hiding it. If he is pushed too far, he can gain a fiercely angry personality. His angry side is so intense that it frightens Rin when it makes itself known. This may be as a result of his Demonic heritage even though he didn't acquire Satan's flames like Rin. The things that annoy him include, but are not limited to, people criticizing Shiro, Rin being "childish", Shura's teasing, being kept out of the loop, people asking him if he's alright and being called "weak".
He doesn't like to partake in 'unseemly' actions. He is usually punctual and lectures Rin on how to behave. As the manga goes on, Yukio gets more and more frustrated with his twin because Rin keeps doing things that put him at risk. While Rin finally accepts what he is and the fact that he is Satan's son, Yukio just can't seem to accept Rin as a brother like he used to.
Yukio started to become frustrated due to his own "weakness" as of late compared to his older brother who he viewed as being "perfect", which started right after his fight with Saburota and his eyes turning blue. This stirred him to find out more about his birth and heritage, causing him to become more and more erratic compared to his usual demeanor attacking even his student and friends. His discovery of the truth caused him to defect from the True Cross Order and even shot Rin in the head displaying a new kind of callousness and coldness.
Manga Version of Yukio's Birth
Anime Version of Yukio's BirthYukio, along wwith Rin, was conceived during his mother's possession by Satan. Though Satan's powers were expected to be split between them, Yukio's body as a fetus proved too weak to handle the Demonic power, which completely transferred to Rin. Nevertheless, Yukio did receive a mashou at birth, causing him to be able to see Demons ever since he could remember. He was always bullied by other kids but Rin would constantly save him. His dream was to become a doctor. He thought he was weak and wanted to become stronger, then Father Fujimoto approached him and asked him if he wanted to become an Exorcist and help protect others.
ChildhoodYukio secretly trained to become an Exorcist since age 7 in order to protect Rin (through the help of Shiro Fujimoto). While both Yukio and Rin are in their first year at True Cross Academy, Yukio is already an instructor at the Exorcist cram school who teaches Anti-Demon Pharmacology to Rin's class. It is often stated that Yukio is a genius, having already acquired the title "Meister" in both the Dragoon and Doctor class, while ordinarily, most people would aim for Meister in one class (both are still fully qualified Exorcists). He is currently ranked a Middle First class Exorcist.
Yukio used to look up to Rin, but as he trained to be an exorcist in secret, he got jealous because Rin always got special treatment and got to be carefree while he constantly worked, training to protect the very brother he had started to loathe.
Yukio was accepted into the True Cross Academy. He began packing his things, then when he finished he went to Fujimoto to see how he was doing. There he also saw Rin. Father Fujimoto then asked him if he could heal Rin's wounds. While he was treating Rin's wounds he told Rin that everyone at the church was worried about him getting fired from all his jobs and getting into fights all the time. Then the next day before Yukio would leave, Father Fujimoto suggested that they will have a party to celebrate Yukio's success. When everyone sat at the table waiting for Rin, Yukio went to look for him. He found Rin on the playground. There he questioned Rin as to why he was fired from his job. They went home together.
When they arrived, Yukio and Rin saw a man and his daughter speaking to Father Fujimoto. When Rin suddenly claims that it wasn't human who attacked the girl but a weird creature. Yukio was surprised that Rin saw the Demons. After they all went to celebrate Yukio's farewell party.
The next day Yukio went early in the morning to the True Cross Academy because his things were sent earlier. He left a note to Rin informing him of that. While Yukio was at the station he called Fujimoto to see if everything was alright, but Fujimoto didn't answer. Yukio thought that something was suspicious and went back.
When Yukio got back home, he was surprised to find the church totally destroyed and the deceased Fujimoto laying on the ground. He also noticed that Rin awakened his powers.
The next day, Yukio went with Rin and Mephisto Pheles to the True Cross Academy. There Yukio gave a speech in front of everyone. He was the center of all gossip and everyone was amazed that he had the highest marks on the entrance exams.
When Rin entered his Exorcism class, he was surprised to see Yukio as his teacher. They're both brothers began to argue with Rin demanding an explanation from Yukio as to why he is involved in all this. Yukio promptly sent the class out into the corridor when Rin spilled blood on the floor, attracting Demons. Yukio then said that he could see Demons since he was born. Then Goblin Demons attacked them after the blood spilled. They both fought the Demons together. At one moment Yukio seemed like he was going to shoot Rin for killing Father, but he didn't. As Yukio pointed his gun at Rin, he told Rin to either turn himself in or just die. When a huge hobgoblin appears behind Yukio, Rin runs at it. Yukio thought Rin was going to kill him. When Rin kills the demon instead, Yukio puts his guns down. Yukio then asked Rin how their father's final moments were. Rin answered that he was very cool. The class then came back into the room shocked by the state of the room.
Then, after, Yukio and Rin went to their rooms, only to Rin's surprise they were sharing one room. Yukio told Rin that he would need to keep watch over him at all times. Rin then agreed to Yukio's challenge.
The next day, Yukio found Rin reading his manga. He told him that instead, he should concentrate on his studies. He told Rin that he needed to go to do a request and go shopping while he's at it. Rin then offered to go with him, telling him that it is a better way to study for him. Yukio said that he could come.
When they arrived Yukio went inside the shop to greet Shiemi's mother who told him that Shiemi's legs are getting worse and worse. He then said that he will have a look at them. Entering the garden, he saw Rin and Shiemi together. He asked Rin why he was there and then told Shiemi that he should have a look at her legs. At first sight, he concluded that it was the work of a Demon. He asked Shiemi if she had had any contact with Demons. While declining, Shiemi collapsed. After that, they took Shiemi back to her grandmother's room. Yukio and Rin talked to her mother about how she never had any time for Shiemi.
When Rin and Shiemi were talking, Yukio came and told Shiemi that they will be able to exorcise the Demon. Angered by this the Demon revealed itself and used Shiemi as a shield. Yukio asked Rin for help which he gladly gave. Yukio realized that he had no other choice but to fire a harmless bullet, tricking the Demon and giving Rin a chance to kill it. After the Demon was killed, Shiemi went to apologize to her mother.
The next day, Yukio introduced Shiemi to the whole class as a new student. Then continued the lesson.
Yukio along with Shura is head of the training. He leads the Exwires to the camp location and explains the task to them. While the Exwires venture into the forest, Yukio stays at camp with Shura. A signal flare is sent up shortly after and Yukio goes to retrieve the ExWires who needs help. On exiting the camp Yukio is attacked by a swarm of moth Demons and surprised at how many and how aggressive they are. While he is fighting the moths, Rin starts fighting Amaimon. Yukio arrives at the battle just as Rin makes a motion to draw his sword. Yukio calls to Rin, saying it is a trap, but Rin draws his sword anyway. Yukio retreats to the Exwires. When Rin is subdued, he stays behind with the Exwires to explain his and Rin's parentage.
Interrupted from a match with Shura. Yukio was sent on a mission to track down the thief who stole the Left Eye of The Impure King. At the scene, a woman with her son named Satoru was walking by as Exorcists told them to move away as the Eye might've been close and may cause infection. Compelled by this Satoru runs past the Exorcist and he is taken hostage by the thief.
Hearing the Satoru's incident, Rin spots Satoru's Mother and promises her that he'll save her son. Unsure of Satoru's safety, Yukio corrects Rin and tells the woman that it is not confirmed that her son will still be alive. Yukio tells Shura to keep an eye on Rin as he and Saburota Todo enter an abandoned apartment where they believe the thief is inside.
As soon as the canary stops singing(meaning that poison gas is nearby) they manage to corner the thief taking Satoru hostage, the thief cracks the glass bottle holding the Eye and as it releases a gas, the thief manages to escape, but that eye was a fake. Saburota betrays Yukio and knocks him down with a kick. Yukio turns his head and sees a Demonised Saburota. Shocked by this, he tells Rin(who just happened to get rid of Shura) to quickly take the boy and run. Yet still, in fear, Yukio cured Satoru of his infection and returned him to his mother. It was later then revealed that the scene was a scheme and now the real Eye has actually been stolen.
Yukio and other Exorcists were sent to track down the Eye.
While hiding in the bushes, Yukio encountered a Demonised Saburota. But instead of attacking him in an instant, Saburota talked Yukio into his true feelings towards Rin. Attempting to stop this, Yukio uncommonly swore and tried shooting him. Being Demonised, Saburota dodged the bullets with ease. Yukio tries hiding within the forest to prepare a solution to getting rid of him, but that doesn't refrain Saburota from continuing their agonizing conversation of growing up to be a weak, feeble being of the world.
While Saburota sits on top of Yukio, pinning him, Yukio shouts and suddenly, there is a burst of blue flames. The flames prove to be from his eyes, that turned demonic and slit pupils when his body apparently activated some sort of defense that triggered blue flames to blast Saburota away from him. When this is all very, Yukio wonders what happened and about his eyes.
Yukio, Shura and many other exorcists got with the ExWires to the beach. Their job is to kill a Kraken that is close to shore. When they get the Kraken to appear, Rin goes to a boat and starts the engine on it. Shiemi asks what he is doing and he starts to reply but is interrupted by the boat lurching into the water. Shiemi promptly falls in the boat face first. Yukio sees them and gets to a different boat. He goes after them but the two ExWires are already in trouble. The boat is what does aside and Rin topples out into the water. Shiemi is grabbed by a tentacle and swung into the air. She screams for Rin but gets Yukio as her hero instead of as they swim into an underwater cave. They meet a giant whale-like demon, who is peaceful. Shiemi gives him food by summoning Nee. While the whale demon attacks the Kraken, Shiemi stands by and tells Yukio to talk to Rin as a brother.
Rin states that he has accepted what he is and that he is Satan's son. He asks Yukio to accept him as well. Yukio tells him that he can't accept that fact and that's that.
The Kraken is killed and everyone goes back to True Cross Academy.
Shura bumps into Yukio and tells that a large number of demons are gathering at a waste research facility but she is unsure if it is related to the demon eaters.
Yukio himself is preoccupied with concern over his eye. During his health exam, he is told that everything is normal. Eventually, he is called to a meeting with the Vatican to discuss his encounter with Saburota Toudou. He is placed under the Contract of Morinath. There, he meets Lewin Light and is asked about his personal opinion about Toudou.
At the festival, Shima reveals himself to be the spy from Illuminati. However, he is also a spy for Mephisto as well. He takes Izumo and they are picked up by a helicopter that takes them back to the Illuminati base.
Rin doesn't want to believe that Shima is a traitor because Shima was the only one who accepted Rin for who he was. he promises to bring both him and Izumo back. They all end up going to Izumo's no drown. They go to the Inari apartments where the Illuminati base is located. They are seen by cameras and challenged. Failed experiments come at them. The experiments can't be killed or die. They're basically like unkillable zombies. They get past them eventually, only to be trapped in separate chambers where each person has their own failed experiment to deal with. While tightening a huge misshapen mutant thing, Lucifer, Demon King of Light, visits Yukio. He shows interest. He knows Yukio has demonic powers that reside in his eyes. He cups Yukio's face in his hands and put his face close to Yukio's and tells him he wants to have Yukio on his side.
He then disappears.
The Exorcist Exam is put at an earlier date so they can have more exorcists to fight demons when the artificial Gehenna gate opens.
He is seen trying to forcefully awaken his demonic powers. Mephisto summons Rin and Yukio to investigate the whereabouts of Shura Kirigakure.
Mephisto Pheles orders Yukio and Rin Okumura to go to Towada Shrine in Aomori prefecture to track down and bring back Shura. Yukio tells Mephisto he would rather go alone, which angers Rin. Mephisto then firmly tells him not to argue and that it is an order. He also tells Yukio that one of his sources told him about the dangerous training he has been engaging in. He looks shocked as Rin asks about the training. Yukio then quickly asks Mephisto a question but is quickly cut off by him. Mephisto tells him that training is not an issue, but not to endanger his life. He then tells Yukio to use the trip as a chance to blow off some steam.
Aboard the train bound for Aomori, Rin is excited as usual about traveling. Yukio asks him if he is ashamed of himself, to which he says why should he be as they were ordered to blow off some steam. Yukio then quickly reminds him that they are there to find Shura. Rin acknowledges him before quickly cutting him off and then exclaiming about eating bento from the train station. After arriving at the station, Yukio suggests asking around to see if any of the locals had seen Shura. Eventually, they get a lead from a taxi driver, saying he drove her to Lake Towada.
Arriving at the lake, Rin complains about most of the shops being closed. Yukio reminds him that it is the offseason and it's 4 in the afternoon. Soon after, Rin asks about where they should stay. Yukio says that he will ask about lodging. He then spots an inn that has some lights on. Upon entering the inn, Rin says it is creepy while Yukio calls out to see if anyone is there. A lone voice then answers back. A little old lady emerges from the darkness and asks if they will be checking in. Yukio then asks her if they have a room for two to which she replies that they have plenty of open rooms. Pleased with her answer, Yukio tells her that they would like to stay. She asks if they came to sightsee even though it is the dreary season to which Rin excitedly answers yes. He then asks if they have an outdoor bath and she says that they do, much to Rin's excitement. Yukio then interrupts him saying that they have work to do. the little old lady tells them not to pretend and that folks tend to do as they please and that she is not one to judge. Yukio flashes a confused look, seemingly confused by the woman's words. Arriving in the room, she asks if it is alright. Yukio says that it is while Rin marvels at the view of the lake from the window. The woman then tells Yukio that they may reserve a private bath.
The woman continues on, telling him that that way, they do not have to worry about what other guests will think. Yukio looks confused and worried as Rin chimes in saying that he prefers an outside bath, before asking Yukio if he does as well. Yukio sheepishly responds that he does. The woman then responds that she will ensure no one disturbs them and that they can enjoy themselves however they wish. Yukio quickly cuts her off, yelling that she does not understand. Rin, totally oblivious to the innuendo being applied, then happily suggests that they hit the outdoor bath.
Outside in the bath, Rin cannot help but be excited as usual while Yukio comments on how exhausted he is. Rin asks Yukio if he wants him to scrub his back and Yukio quickly tells him no thank you. He then lets out a sigh and comments that he wishes he could be as laid back as Rin is. Rin then suddenly has an outburst, saying that the mission so far has been a blast and apologizing to Shura. After calling themselves the Exorcist brothers, Yukio pies in saying that is a stupid name. Rin then tells him not to be like that and then asks him to talk with him. Rin then immediately asks about the "dangerous training" Mephisto spoke about. Yukio looks quite surprised when Rin asks. Rin asks if Yukio is ok after he does not respond. He says that he is fine and that the training is just shooting practice.
Yukio quickly changes the topic and asks Rin how he has been doing. Rin goes on to explain that he accidentally told Shiemi that he liked her. Yukio seems quite surprised by Rin's admission. He then asks Rin about what she said. Rin tells him that Shiemi said that they were just friends. He then says that he should not have said anything and that now, things will be weird between them. Rin then says that he thought Shiemi liked Yukio but said they are just friends also. Yukio tells him that he does not understand anything, that she is a good student and looks up to him, and always has since they met. He then says that if she knew the real him, that she would despise him. Rin is surprised by Yukio's statement and say the Shiemi has said she admires him and would never say she hated him. Yukio then says that he is getting dizzy and that he is getting out of the bath.
Yukio is seen getting visited by the exwires. He tells them he'll be out of the hospital in four days. He tells Shiemi the exorcist certification exam is in three days. He asks her if she wants to be an exorcist. Yukio gets out of the hospital early which surprises the exwires. He tells Rin that Gramps passed away and they go to his funeral. Yukio and the exwires try to figure out why Shiemi doesn't want to be an exorcist.
Ryuji and Lightning have been investigating the Okumura twins' birth and Yukio is smart enough to connect the dots. He doesn't know most of what the two have learned, only that they played a part in Gramps's death. (One of the things Ryuji and Lightning find out is that Shiro was actually a clone of Azazel, made by the Illuminati. It appears that Shiro escaped or was let free of the Illuminati lab in early adulthood or his late teenage years, via the photo in the file that has his information.)
However, Christmas time is rolling around along with the twins birthday(or at least the day Shiro found them. They don't know their actual birthday) so the ExWires throw a party in celebration. At said party, Shura reveals that she knew Rin and Yukio's mother, Yuri. She ￼tells hem she was kind and beautiful. She also tells Rin that he has his mother's eyes. All the while, Yukio has flashbacks of memories from when he and Rin were kids.
In memory, Yukio asks about his parents. Shiro tells him he found the boys on December 27 and that he didn't know the twins' parents. Yukio pries for more details and Rin tells him to stop. He says that if Shiro said he didn't know them, then leave him be. Shiro was their father, so why did it matter? But Yukio is also curious and always wants to get to the bottom of things, so even now, he still wants to know. He also wants to know why Rin never cared about knowing their parents.
After the party, Rin and Yukio are getting ready for bed in their shared dorm room. Yukio grills Rin for not caring about their parents. Rin is confused as to why Yukio is hell-bent on knowing about their birth and their mother. Yukio seemingly loses it and yells at Rin, effectively scaring said half-demon. Then Later in the arc, Yukio holds Ryuji at gunpoint when Ryuji tells him that he can't give away anything he's learned on his investigation with Lightning. Everyone is now getting freaked out by Yukio's irrational behavior. Lightning the attempts to talk with Yukio about why he is investigating the Blue Night but Yukio dismisses him and Lightning remarks he can't help someone who refuses to be helped.
As Lightning is being arrested for assaulting a member of the True Cross he slips an object to Yukio and mutters what at first seems like gibberish into his ear before he is taken away. The object is a USB drive and the gibberish was a password. Yukio opens the files and sees that Shiro Fujimoto is a clone of Azazel but there is no further information about his mother or he and Rin's birth. Out of frustration, he destroys the computer. He thinks back to a memory of Shura telling him that Father Fujimoto had once referred to him and Rin as weapons and concludes that this along with the file information means that Fujimoto and the Order must be in league with the Illuminati, referring to the Order as "Humans sacrificing humans.". He goes outside and smashes the computer against the tree. Orders are given for his team to switch and he goes into the fight. Shooting demons and acting recklessly, his superior finds him and says he should go home out of concern. Yukio doesn't want to return to the dorms to see Rin or be near True Cross Academy, instead, he walks alone in the rain. Sitting on a staircase near Shiemi's family store Shiemi comes outside and talks to him, recalling when they had met when they were younger in the same fashion. Yukio and Shiemi sit inside and Shiemi asks if anything is wrong, he denies it and says he has been working hard. Yukio then hugs her and apologizes for being so gloomy recently. Yukio then goes on to say that he used to always care about gaining recognition and working hard but recently that motivation has left him, he states he has no friends and that he is alone. Shiemi tells him that she is his friend and that she and Rin have been worried about him. This suddenly enrages him, he screams "WHO ASKED YOU?" and violently shoves her to the floor. Yukio then turns and runs out of the store with Shiemi crying and calling after him.
He stands alone in a secluded area. Yukio says that he let his own pathetic issues hurt such a kind person and that he is truly weak, he says he is tired before putting one of his pistols to his temple and pulls the trigger, intending to take his own life. The bullet is deflected from his temple and blue fire comes out of his eyes as Yukio screams and hears Satan speak to him in his mind, Satan mocks him and asks him if he really thought he would be able to die so easily. The amount of fire that Yukio is releasing is larger than ever before. Shima then approaches from the shadows as Yukio is hunched over clutching his eyes and states that "That was quite the nice look on your face before." Yukio then looks up at him and removes his hands from his face revealing his eyes which are demonic and slit pupils.
Meister & Abilities
Yukio is an extraordinary Exorcist and was instructed by one of the most powerful Exorcists in the world, Shiro Fujimoto. He obtained his official Exorcist license at the age of thirteen, as well as becoming the Order's youngest teacher, specializing in Anti-Demon Pharmacology, at the age of fifteen. Due to his unique heritage, he acquired a mashou from Rin at birth.
Though Yukio hasn't inherited the same Blue Flames and demonic traits as his older brother, in his fight against Saburota, he is shown to possess blue demonic eyes, which caused the demon eater to retreat through sheer instinct; he later stated that those weren't his eyes. Since then, Yuki has continued to explore this and even tried to jump off a roof, which also resulted in his eyes turning blue and creating a significant crater in the process in the aftermath. He later tried to commit suicide by shooting himself in the head, causing his eyes to turn blue again with Satan talking to him and using his blue flames to save him, then he could later break Kurikara causing his demon heart to Rin. Lucifer later explained that due to his left eye is a window for Satan to interact with Assiah from Gehenna.
Flame Resistance: It is later revealed that Yukio has an unnatural resistance to red, black and blue flames to the point where he didn't suffer from the slightest burn.
Demon Form (Anime): He is shown to have awakened his demonic heritage in the first season's anime after he was first possessed by Satan, which granted him demonic traits such as long ears. Yukio also is shown to have blue flames much like Rin and his blood is that of a Demon.
Despite his youth, Yukio's medical abilities are top-notch. He was able to treat Noriko Paku after being injured by a Naberius that Igor Neuhaus summoned, after being treated by Shiemi. In the manga, during the theft of the left eye of the Impure King, he cured a child named Satoru by inserting needles into the miasmatic boils on his body without rupturing the membranes of the cells, demonstrating advanced knowledge of cellular biology. This is made further impressive as at the time, Yukio was also infected by the miasma while left reeling by the words of a possessed Saburota Todo. When he and his brother were young, he would treat Rin's injuries whenever he came home after getting into a fight.
In addition to his medical skills, Yukio's competency in his Meister extends to teaching. He is considered to be a qualified teacher of basic Anti-Demon Pharmacology at the age of fifteen and is the youngest person in the order to do so.
Yukio's second and offensive Meister is Dragoon, a gunslinger. Yukio can shoot his targets with impressive accuracy, all the while maintaining a calm and even disposition. He has demonstrated the ability to shoot Demons behind his back without even looking at them, as well as destroying giant Demons with his handguns. Yukio's weapons of choice are dual handguns that may have been modified for rapid-fire. He is able to keep up with Shura, an Exorcist 2 Ranks above him, in a combat simulation test. Yukio also has some knowledge of the fighting elemental Demons, as shown when he fought a fire Demon using water-attributed bullets. In the anime, he has also been seen using a shotgun.
He also appears to be very skilled in long-distance shooting as he is shown successfully and accurately shooting the Kraken clones at a great distance with a sniper rifle. After leaving the True Cross Order and later joining Illuminati, Yuki was handed the Armumahel Pistols, which are special pistols that are able to fatally injure even high-level demons , at the cost of losing his memories, but his flame resistance making them perfect for him.
Although Yukio does not have Meister training as a Tamer, he is able to summon multiple Naiads and also perform a spell with them. However, his lack of stamina and experience in summoning Demons makes it difficult to maintain the summon for long periods of time. Saburota notes that this was the first time Yukio has summoned demons.
- Naiads (
水精Naiasu): Yuki is able to summon water demons in order to counter the fire abilities of Saburota Todo gained from eating Karura.
- His name means "man of snow" in kanji, alluding to his pale features and stoic attitude.
- According to the Ao no Exorcist Guidebook, Kazue Katō said that originally, Yukio and Rin weren't Exorcists, but anti-paranormal agents who exterminated supernatural creatures.
- In the first popularity poll, Yukio ranked first, with a total of 2529 votes.
- He is popular with girls, though he finds it difficult to reject them.
- His favorite food is seafood, especially sashimi.
- His known pastimes are: formulating plans and reading Jump Square every month.
- His favorite manga genres are; comedy, horror, suspense.
- He averages 4 hours of sleep each night.
- His favorite animals are penguins.
- He is ranked 5-6th on Rin's 'cool dude' list which is the same rank as Kuro, Rin's familiar.
- He is embarrassed and extremely bothered by how many moles he has.
- Yukio is ambidextrous.
- The original concept had Yukio and Rin's names switched around, therefore, his name was Rin. His hairstyle was also similar to Rin's.
- Kazue Katō intended on giving him stress-related asthma, making him always have an inhaler around. This concept had him slightly psychic and sometimes prescient. It is also said that he was supposed to be interested in computers and a feminist.
- The English translation of Volume 2 mistakenly states that Yukio has a Meister in Dragoon and Aria, rather than Dragoon and Doctor.
- (To Rin Okumura) "You utter fool, brother...Why did you come up with this ridiculous idea of becoming an Exorcist? Revenge? Some kind of twisted sense of atonement towards Father? If you truly have the nerve to feel that way...then you should give yourself up to Order Headquarters...or just die, please."
- (To Mephisto Pheles) "From...from now on...I will protect my brother in Father's stead."
- (To himself) "I...ever since I was little...I looked up for my brother. But...while I looked up to him, at the same time, I've actually...always...always...always...I always...found it hard to accept."
- (To Saburota Todo) "I...I both love and hate my brother!... But even more than that...most of all, I hated my weak younger self. The one I really hate, most of all, is myself!"
- (To himself) "I hate myself. That's why I wanted to become like father and brother, therefore I've always...(remembers Rin saying «I'll surpass you!») That's actually my line, brother."
- ↑ Ao no Exorcist Manga: Chapter 74, Page 3
- ↑ Ao no Exorcist Manga: Chapter 74, Pages 4-6
- ↑ Ao no Exorcist Manga: Chapter 74, Pages 8-11
- ↑ Ao no Exorcist Manga: Chapter 74, Pages 12-16
- ↑ Ao no Exorcist Manga: Chapter 74, Page 17
- ↑ Ao no Exorcist Manga: Chapter 74, Pages 18-19
- ↑ Ao no Exorcist Manga: Chapter 74, Pages 20-22
- ↑ Ao no Exorcist Manga: Chapter 93,
- ↑ Ao no Exorcist Manga: Chapter 30, Chapter 32
- ↑ Ao no Exorcist Manga: Chapter 93, Chapter 28
- ↑ Ao no Exorcist Manga: Chapter 110, Chapter 8
- ↑ Ao no Exorcist Manga: Chapter 37
- ↑ Ao no Exorcist Manga: Chapter 110, Chapter 12
- ↑ Ao no Exorcist Manga: Chapter 29, Pages 20-23
- ↑ Ao no Exorcist Ura-Eku 1
- ↑ Ao no Exorcist Manga: Chapter 2, Pages 33-35
- ↑ Ao no Exorcist Manga: Chapter 2, Page 53