The School Nurse Files — Characters & Cast

Initially: get through the day, contain the damage, resent the assignment. Increasingly: protect specific children she has come to know, and refuse to let institutions decide who is expendable. By the finale her motivation is anger — a righteous, personal fury at being used — which is what carries her back into a fight she cannot win alone.

She begins as a burnt-out professional treating her gift as a chore, deflecting intimacy with sarcasm and doing the job because nobody else can. Contact with In-pyo restores her stamina and, gradually, her willingness to be known.

The midpoint flashback to her school years and a friend from her past reveals that her flippancy is armor over grief, and that she has been rescuing people since she was a child. The final stretch strips her down — loss of power, betrayal by someone close — so that her return to the school is a choice rather than a reflex. She ends the series still exhausted, still underpaid, but no longer alone in it.

At first, curiosity and a limp sense of obligation to the family school. Later, genuine loyalty to Eun-young and a growing need to know what his family buried and what it cost others.

A Chinese-language teacher and heir of the school's founding family, he starts as a passive presence — mild, slightly dorky, unable to see a single jelly. His body's protective energy field makes him useful before he is brave.

His development is a movement from being a resource to being a participant: from lending his hand to actively investigating, questioning his family's legacy and standing beside Eun-young at the end. His faith in someone whose reality he cannot perceive is the quiet moral spine of the show.

Access and appetite — using the school's hidden power and its most isolated students for personal ends, offering shortcuts to those the social order has already broken.

Introduced as a fellow teacher who, unlike everyone else, can also see the jellies — briefly raising the hope that Eun-young has found kin. That hope curdles: Mackenzie's interest in the school basement and in vulnerable students proves predatory rather than protective.

The character functions as the series' argument that sight without care is worse than blindness, and becomes the human face of the danger before the supernatural threat scales up.

To belong and to be left alone, in that order; later, simply to survive what has been placed inside her.

A transfer student from abroad, immediately marked as an outsider and bullied, who tells Eun-young that she is a "mite-eater." What sounds like a strange confession turns out to be literal.

Her arc moves from victim of ordinary cruelty to a body that carries something monstrous, culminating in the surgery that reveals an enormous engraved mite inside her — the clearest statement of the show's idea that children absorb what adults refuse to handle.