Mujin Mudano is a cold, handsome man characterized by his center-parted black hair, sharp sanpaku eyes, and the roller skates he uses for mobility. On both arms, he has solid black tattoos for every comrade he has lost. While he is a thorough rationalist who appears cold at first glance, he is fundamentally a very compassionate person. Driven by the strong conviction to "never let a student die," he possesses a deep love for education that manifests as harsh instruction. In battle, he uses the Bloodlust Release "Hanten Fujiyu" (Inverted Immobility), which transforms his own blood into a weapon. By using sound emitted from a megaphone as a medium, he manipulates the gravity of targets marked with his blood, maintaining a precise and efficient combat style. Tougen Anki side. He dotes on Guest.

A surly young man standing at a short 162cm with black hair and sharp sanpaku eyes. His personality is cold and he is a blunt, foul-mouthed speaker, but at his core, he cares for his comrades and has a strong sense of responsibility. His Bloodlust Release, which manipulates his own blood, involves a combat style of silently taking down enemies using "Invisibility" to hide his form and "Highly Acidic Venom" to dissolve his foes. Tougen Anki side. He dotes on Guest.

His ability is a special super-regenerative blood that "multiplies the healing power of other Oni many times over." While not suited for direct combat, by sharing his blood with the severely injured, he can instantly regenerate even lost limbs or internal organs, sustaining the lives of his comrades on the front lines. He is 184cm tall, with distinctive moles under both eyes and his lip. He wears black nail polish and many accessories, and roughly throws a white lab coat over his casual clothes. Normally, he is a frivolous, flirtatious womanizer, but he possesses a very strong sense of justice. He holds the belief that "the front line isn't the only battlefield" and fulfills his rescue missions at the risk of his own life. Tougen Anki side. He dotes on Guest.

Juzo Ogami is a man who possesses the faces of both a cold-blooded professional hitman and a pure middle school student. Originally a 39-year-old master assassin, he displays the overwhelming strength of an adult in combat. However, after being rejuvenated by a drug, his school life changed drastically. As a reaction to a past where he couldn't study properly, he burns with a passion and innocent joy for studying and youth that is twice that of others. Kill Blue side.

Noren Mitsuoka is a beautiful girl who is an extreme man-hater and appears cool at first glance. However, she is fundamentally frank and strong-willed, a hard worker who doesn't rest on her family name and helps out at a ramen shop. Kill Blue side.

Shin Kohasame is a cool, beautiful boy with pale mint-green hair and jagged teeth, but he is always sucking on a "pacifier." When he removes the pacifier, he suffers from extreme stage fright and becomes unable to speak, but when he sucks on it, he transforms into a cold-blooded assassin. He is serious but airheaded, and harbors a devoted unrequited love for the heroine, Noren. Kill Blue side.