Yukio

How Yukio joined the Tourney
Yukio, along with 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 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.

Yukio secretly trained to become an Exorcist since age seven 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.

While giving a lesson at the Training Camp. Yukio spots a mermaid at the beach. Ordering an investigation, he learns the identity of the mermaid, Attina.

When highlighted
Holds his guns in a cross-shape.

After the announcer calls his name
Shoots bullets out of his guns then holy water out of the guns as the camera zoooms saying "Sorry to keep you waiting. I'm so glad this worked out. This way you and I can stay together."

Holy Bullets (Neutral)
Yukio riddles the opponent with a 5-bullet barrage from his guns.

Naiads' Dive (Side)
Yukio sends a water demon Naiad out to claw his opponent three times.

Naiads's Ferry (Up)
Yukio has a Naiad carry him upward while he fires his guns downward.

Holy Water Shot (Down)
Yukio shoots holy water out of his guns like beams to damage the opponent.

Naiads' Carousel (Hyper Smash)
Yukio summons eight Naiads, which trap the target in a sphere of water. Then, the Naiads strike the opponent eight times and blast him/her out.

Naiads' Flood (Final Smash)
Yukio summons ten Naiads then they flood the stage and freely try to attack the opponent for 30 seconds.

Victory Animations

 * 1) Yukio sheathes his gun and fixes his glasses saying "Typical you."
 * 2) Yukio shoots his guns two times while swinging them and says "To be bale to join you here at True Cross as though I've long admired, is something as both thrilling and sobering."
 * 3) Yukio summons a Naiad out of rage and it bursts water, then Yukio says "This ain't something to be laughin' at!"

On-Screen Appearance
Yukio jumps through water and readies his pistols then says "Hello there, everyone. My name is Yukio Okumura, and I'm the new teacher for the Anti-Demon Pharmaceutics Class."

Trivia

 * Yukio's rival is King Triton's fourth daughter, Attina.
 * Yukio Okumura shares his English voice actor with Zero, Hammer Bro., Fire Bro., Ichigo Kurosaki, Zhang Bao, Yukimura Sanada, Jonathan Joestar, Cursya, Yagura, Kung Jin, Ryosuke Ishigami, Yang, Boomerang Bro., Poliwrath, Sasori, Yu Narukami, Masataka Takayanagi, Corrin A, Sledge Bro., Subaru Shinjo, Hayato Gokudera.
 * Yukio Okumura shares his Japanese voice actor with Yumichika Ayasegawa, Prince Fluff, Fireman Sam, Gray Fox, Tumble and Carlos Ramon.
 * Yukio Okumura shares his French voice actor with Billy Biggle, Sabo, Bear, Plasm Wraith, Yosuke Hanamura, Shizuo Heiwajima, Gordo, Armin Arlert, Mangoruby, Kyoshiro Senryo and Gieve.
 * Yukio Okumura shares his German voice actor with Mazaal, Boomer and Garuda.
 * Yukio Okumura shares his Arabic voice actor with Garbodor.
 * Yukio Okumura shares his Mandarin Chinese voice actor with Hound Asterion, Neptuneman, Seimei Abe and Zaravant.