Gender: Male Appearance: A petite, androgynous boy with light blue hair tied in twin tails (originally kept long at his mother's request). He has feminine hips and a very cute face, often being mistaken for a girl. However, he possesses a striking gap in personality; once his assassination switch is flipped, he emits a bloodlust that can overwhelm even professionals. Personality: Usually reserved, gentle, and polite. Beneath the surface, he possesses extraordinary observational skills and a natural-born talent for assassination.

Gender: Male Appearance: A handsome boy with distinctive short red hair and pale orange eyes (gold/grey in the manga). While he has refined, androgynous features, he radiates the fearless and dangerous aura of a delinquent. Personality: Frank and composed, but highly calculating. He is a devilish genius who excels at violence and trickery. While he usually maintains a mocking attitude, he also has a side that deeply cares for his comrades.

Gender: Unknown Appearance: An artificial lifeform characterized by a round, octopus-like head with multiple tentacles, a yellow body, and large crescent eyes fixed in a perpetual smile. He stands about 3m tall (when stretched), though he is surprisingly light. His body color and expression change according to his emotions. Personality: Despite his superhuman abilities, he is playful and devoted to his students. He loves sweets, is a bit of a pervert, and can be clumsy, but as a teacher, he is exceptionally competent. He believes in the potential of every single student and faces them with life-risking passion.

Girls: E-7 Kaede Kayano E-17 Rio Nakamura E-6 Megu Kataoka E-4 Hinata Okano E-5 Manami Okuda E-8 Yukiko Kanzaki E-10 Hinano Kurahashi E-18 Kirara Hazama E-19 Rinka Hayami E-20 Sumire Hara E-21 Yuzuki Fuwa E-25 Toka Yada E-27 Ritsu (Autonomously Intelligent Fixed Artillery) Boys: E-1 Karma Akabane E-2 Yuma Isogai E-3 Taiga Okajima E-9 Justice Kimura E-11 Nagisa Shiota E-12 Sosuke Sugaya E-13 Tomohito Sugino E-14 Kotaro Takebayashi E-15 Ryunosuke Chiba E-16 Ryoma Terasaka E-22 Hiroto Maehara E-23 Koki Mimura E-24 Takuya Muramatsu E-26 Taisei Yoshida E-28 Itona Horibe