Osiris Red Dorm

The Osiris Red Dorm is one of the three dormitories for students at Duel Academia's Central Branch. Initially, the dorm was meant to house the students with the lowest grades, earning it the reputation of being the slacker dorm. In later years, it has been repurposed with the intent to house students with supernatural powers, to give them the opportunity to connect with other students with similar powers, and to give them a space in which to understand their powers in a safe space.

Underclassmen Dorm
Initially the only dormitory for Osiris, the underclassmen dorm is a small building with two floors, consisting of approximately eight total rooms and one larger room, an addition built by Jun Manjoume during his stay in Osiris Red, as well as a small cafeteria. The rooms open out onto a patio with no enclosed hallways, and looks out at the ocean at the back. Each room can host up to three students, though they are usually populated with only two per room.

The original Osiris Dorm was once part of a seal meant to maintain the confinement of the Three Phantasms, which was the reason for it being placed so far out of the way from the main school.

Yu-Gi-Oh! GX

 * Dorm Advisor (Room 1-6): Daitokuji
 * Room 1-1: Judai Yuki, Shou Marufuji, and Hayato Maeda
 * Room 1-9: Jun Manjoume, Asuka Tenjoin (temporarily), Rei Saotome (temporarily)

Red Days

 * Dorm Advisor (Room 1-6): Judai Yuki
 * Room 1-1: Saki Yamaguchi and Miu Ueno
 * Room 1-2: Taiki Hayashi and Taro Inugawa
 * Room 1-3: Nina Orlando and Anani Ivanova
 * Room 1-4: Morgan Smith and Akiara Tanaka
 * Room 1-5: Minato Fujita and Hanako Kawaguchi

Osiris Blues

 * Dorm Advisor (Room 1-6): Judai Yuki
 * Room 1-1: Haruka Matsushita and Keiko Ueda
 * Room 1-2: Mi-Gyeong Nah and Harue Onaga
 * Room 1-3: Kayoko Hamasaki and Diana Velis
 * Room 1-4: Takako Inoue, Mylene Masson, and Toitoi

Upperclassman Dorm
The upperclassman dorm was a later addition to the school, to expand the space available to Osiris Dorm after the program for powered students was developed. The dorm is larger than the underclassman dorm and entirely enclosed, located a little ways away into the woods near the underclassman dorm. The dorm is two floors and consists of sixteen total rooms, plus a dorm advisor's room, a communal bath/showers, and a cafeteria.

The upperclassman dorm is plagued with several small hauntings, a result of a former student, Hibike Saito, having performed numerous demon-summoning rituals in the dorm that have yet to be exorcised.

Red Days

 * Dorm Advisor: Johan Andersen
 * Room 2-1: Lin Wen and Ren Akiyama
 * Room 2-2: Reina Togo and Jian Xun
 * Room 2-3: Mostyn Nakahara and Lindbloom Oshiro
 * Room 2-4: Ji-U Ishtar Kaiba and Eun Ishtar Kaiba
 * Room 3-5: Saya Nishimura and Hibike Saito
 * Room 3-6: Isamu Mori and Elias Thorn
 * Room 3-7: Kotone Mizushima and Maristella Acquati

Osiris Blues

 * Dorm Advisor: Johan Andersen
 * Room 2-4: Minato Fujita and Hanako Kawaguchi
 * Room 2-5: Morgan Smith and Akiara Tanaka
 * Room 2-6: Nina Orlando and Anani Ivanova
 * Room 2-7: Taiki Hayashi and Taro Inugawa
 * Room 2-8: Saki Yamaguchi and Miu Ueno
 * Room 3-1: Lin Wen and Ren Akiyama
 * Room 3-2: Reina Togo and Jian Xun
 * Room 3-3: Mostyn Nakahara and Lindbloom Oshiro
 * Room 3-4: Ji-U Ishtar Kaiba and Eun Ishtar Kaiba