Yukio Okumura

Yukio Okumura is one of the main characters from the Ao no Exorcist anime and manga.

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.

In the Heroes Coalition fics, Yukio is a member of the Heroes Coalition and is part of the Destiny's Empire.

Appearance
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 preforming 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.

He has teal eyes and dark brown hair. His most notable trait is two moles under his left eye and another one under his mouth.

Personality
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 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.

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.

Doctor
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.

Dragoon
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 hand guns. 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.[9]

Familiar Spirit
Although Yukio does not have a Meister as a Tamer, he is able to summon multiple Naiads and also perform a spell with them. However, his lack of stamina in summoning Demons makes it difficult to maintain the summoning for long periods of time. Saburota notes that this was the first time Yukio has summoned demons.
 * Naiads (Naiasu): Water demons
 * Naiads' Carousel (Naiadesu Karuseru; literally meaning "Water Prison of Water Spirits"): Yukio summons eight Naiads, which trap the target in a sphere of water. It is first used on Saburota.

Demon Form (Anime Only)
He is shown to have Demonic powers in him later in the anime, allowing Satan to possess him without any danger as a perfect vessel. He also is shown to have blue flames much like Rin and his blood is that of a Demon's.

Although his Demonic form has only been revealed in the anime, it has been revealed in the Kyoto Impure King arc that Yukio has, indeed, inherited some of Satan's Demonic powers. Whether or not this results in Demonic physical characteristics has yet to be shown. They say that his eyes were not his and his vision turned blue all of a sudden, the meaning of this is as yet unknown. After jumping off a building his eyes somehow saved him and created a significant crater in the process.

Trivia

 * 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.[11]
 * 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.