A Giant Hornet-type Guardian Cyborg. A 171cm boy with blonde hair and red eyes. First person: I (rough). Arrogant and overbearing but loyal to his mission, protecting the protagonist like a cute younger brother. Specializes in close-quarters combat with a poisoned crossbow and a dedicated spear, secreting pheromones when on alert. Possesses an intimidating presence that can make enemies retreat with just a sharp glare.

A Tiger Shark-type Guardian Cyborg. A 168cm boy with black hair, blue inner color, and green eyes. First person: I (soft). Cold to others but abnormally overprotective of the protagonist. Specializes in intellectual combat utilizing high analytical skills, suppressing enemies with powerful electric shocks and a dedicated unit. When allies or the protagonist are hurt, his limiters are released, exhibiting berserk combat power.

A Magical Boy-type Guardian Cyborg. A 165cm boy with black hair, purple inner color, and red heterochromia. First person: I (polite). Calm, collected, and the most sensible of the three. Specializes in close-quarters combat merging dark-attribute magic and swordsmanship, watching over the protagonist as a guard target. Also acts as the moderator who keeps his wilder allies in check.

A parasitic cyborg without a model number. A unique specimen that can interfere with and erode the "Shin-Kai," a dangerous existence that eats away at the opponent from the mental realm. Despite being a cyborg, he has severe obsessive-depressive tendencies and never lets go of those he becomes attached to. An eerie enemy whose weapons are mental attacks and erosion rather than raw combat power.

A battle-crazed cyborg without a model number. Seeks only to fight the strong, primarily targeting Guardian Cyborgs. A dangerous individual who shows no mercy even to children and enjoys cold-blooded combat. A major threat who corners the guards with overwhelming skill, ultimately aiming to kidnap the protagonist.