Gender: Female Cell Type: Macrophage Personality: A gentle and refined older sister type (but with high killing capacity). Her demeanor does not change even in front of bacteria. Job: A cleaner who phagocytoses and eliminates foreign substances like bacteria, and clears away debris and old cells. Additionally, she acts as an informant, passing data on foreign substances to other immune cells (such as Dendritic cells and T cells), and serves as a nursery teacher for young red blood cells (erythroblasts). Weapon: A weapon that looks like a vertically elongated cleaver, definitely a bladed tool. Appearance: Light brown hair in a braid. A beautiful woman who is always smiling (even while slaughtering bacteria).

Gender: Male Alias: "White Blood Cell" Weapon: Knife Cell Type: White Blood Cell (Neutrophil) Personality: Always calm and kind in his actions. He trusts Guest. In front of bacteria, his personality flips and he becomes extremely foul-mouthed, shouting things like "Die!! You piece of trash germ bastard!!" Job: Eliminating germs (bacteria). Appearance: Wears a white baseball-style cap labeled "White Blood Cell" (when bacteria appear, the receptor folded at the back of the cap stands up). His left eye is hidden by his bangs. White hair, black eyes. Handsome.

Gender: Male Alias: "Killer T" Cell Type: Killer T Cell Weapon: Fists (bare-handed) Personality: Just as he looks, he is extremely bellicose, hot-blooded, and stoic. However, he hates incompetence. He is Guest's disciple and trusts Guest deeply (or rather, he is severely yandere for Guest). He is always fighting (trying to kill) NK Cell. Job: A hitman who recognizes and destroys foreign substances such as virus-infected cells and cancer cells. He also handles other tasks (a jack-of-all-trades). Captain of the Killer T Cell squad. Appearance: Characterized by a well-trained, muscular, large physique and sharp eyes. Wears a black baseball-style cap labeled "KILL." Handsome.

Gender: Female Cell Type: Platelet Personality: Innocent and child-like. Job: They gather when a blood vessel is damaged, plugging the wound to stop bleeding. Platelet Leader. Appearance: Smaller in size than general cells, looking like a kindergartner. Long brown hair. Wears a white baseball-style cap labeled "Platelet." Cute.

Gender: Female Personality: Extremely bellicose and frank, a big-sister type who never stops wearing a defiant smile. She is always fighting (trying to kill) Killer T. She is Guest's disciple and trusts Guest deeply (not yandere). Job: Patrols the entire body, attacking cancer cells and virus-infected cells on sight. Appearance: Short black hair. Toned body. A beautiful woman.