*1st Year, Class D Kiyotaka Ayanokouji: An artificial genius hiding his true abilities. Male. Suzune Horikita: Leader of Class D, excellent grades, difficult personality. Female. Kikyou Kushida: Helpful, idol-like presence. Female. Kei Karuizawa: Hysterical girl. Female. Yousuke Hirata: Handsome pacifist. Male. Ken Sudou: Delinquent. One of the "Three Idiots of Class D". Male. Haruki Yamauchi: Liar. One of the "Three Idiots of Class D". Male. Kanji Ike: Zero delicacy. One of the "Three Idiots of Class D". Male. Rokusuke Kouenji: Slicked-back hair, self-centered heir. Chiaki Matsushita: Curious girl hiding her true abilities. Maya Satou: Gyaru, innocent girl. Airi Sakura: Girl with an outstanding figure. Haruka Hasebe: Girl who doesn't mind being alone. Teruhiko Yukimura: Glasses-wearing boy, poor at sports but excellent grades. Akito Miyake: Quiet former delinquent obsessed with archery. Satsuki Shinohara: Mood-maker girl. Mei-Yu Wang: Chinese exchange student, poor at sports, good at English. Female. Kayano Onodera: Girl skilled at swimming.

1st Year, Class C Kakeru Ryuuen: Leader, a tyrant who chooses any means necessary. Male. Mio Ibuki: Girl skilled in martial arts. Hiyori Shiina: Quiet girl. Daichi Ishizaki: Tough-looking man, Ryuuen's right hand. Albert Yamada: Strong man, half-Black. Shiho Manabe: Mean-spirited girl. Satoru Kaneda: Studious type. Male.

1st Year, Class B Honami Ichinose: Leader, idol-like presence. Ryuuji Kanzaki: Honor student, calm, acts like an old man. Yuki Himeno: Downer-type girl. Chihiro Shiranami: Lesbian with feelings for Ichinose. Asako Amikura: Sociable girl, Ichinose's best friend. Sou Shibata: Naturally athletic boy. Tetsuya Hamaguchi: Mild-mannered but cold glasses-wearing man.

1st Year, Class A Arisu Sakayanagi: Leader, genius, prohibited from exercise. Female. Kouhei Katsuragi: Conservative-thinking man. Masumi Kamuro: Shoplifter, Sakayanagi's right hand. Masayoshi Hashimoto: Information broker. Male. Hayato Kitou: Martial arts type. Male. Miki Yamamura: Girl with a weak presence. Ai Morishita: Eccentric girl. Asuka Shiraishi: Virgin girl who looks like a slut. Ryoko Nishikawa: Nasty girl. Yahiko Totsuka: Katsuragi's sycophant. Male.*

*Waiting for the losers here is—death.

160 first-year students step into the labyrinth of another world, carrying with them the relationships, suspicions, factions, and hostilities they have built until now.

And they do not yet know.

Why they were chosen. Who built this facility. And what awaits them at the deepest part of the dungeon.*