Yuuri Oreki

Yuuri Oreki is a teacher from Hagun Academy and the homeroom teacher from Ikki's class. She wields the Device Violet Pain (血染めの海原, Chizome no Umihara, lit., "blood-stained ocean") and is known by the nickname "Jolly Roger" (死の宣告, Shi no Senkoku, lit., "Death Sentence".

Appearance
Yuuri is a young beautiful woman, although she does look sick most of the time due to her weak constitution and vomiting most of the time. She has long dark hair, with bangs that cover her forehead, as well as covering her ears completely, it is also long enough that it goes down to her back. She is usually seen wearing a long sleeved white blouse, as well as a long dark skirt, and high heels.

Personality
Yuuri is a kind hearted woman who cares for all her students, going as far as to fake a child and hyper-like personality to reduce the tension of the first year students. She also constantly encourages her students to have faith in themselves.

History
Yuuri is known to have a weak constitution, vomitting one litre of blood a day since childhood. She was also Ikki's examiner during his entrance examination day, giving Ikki a chance to enter the school.

New Term, Reunion and Rebellion
Yuuri welcomed her new students on their first day, explaining the new rules of the school set up by the new director, Kurono Shinguuji, for the upcoming Seven Stars Sword Art Festival and encouraging her students to take part in the Seven Stars Sword Art Festival seeing as a chance for them. The homeroom then ended abruptly as Yuuri starts vomiting blood, as she was taken to the infirmary by Ikki.

Debut Battle and Vow
Yuuri is next seen, doing the announcement, with another unnamed announcer, announcing the battle, Shizuku, and Soga, and complementing Shizuku as she easily defeat their opponent.

Impossible Victory, Decisive Battle, and New Beginnings
Yuuri is then seen finding a broken building, and a sorrowful Ikki. He tells her what had happened to the building, and with Ayase, stating that Ayase will probably cheat in their match. Yuuri offers to keep a close eye on Ayase, but Ikki tells her that he doesn't want Yuuri to call out Ayase, as he wants to help her not beat her. Yuuri agrees, and does not say anything while she commentates on the match believing in her student Ikki.

Siege, Reunion and Trap
Yuuri serves as the observer and judge for Ikki's 18th and 19th selection battle matches while he was detained inside the Japan branch headquarters, noticing that Ikki's sickness is too unnatural. Yuuri is later seen among one of the supporters for Ikki during his match against Tohka Todo, encouraging him.