She is the mother of Seong-ah. After her daughter's death, [Eun-mi attempted to get the help of Ji-won in order to channel the power of Qi and perform a ritual to resurrect her using three people, a person who calls the dead (Choi Eun-mi), a person who can break the seals using the talismans (one who sees ghosts - the music teacher, Ji-won) and a sacrifice (Na-Yeong), but due to the master of the labyrinth possessing Na-Yeong, it disallowed itself to lose its host, interfering in the ritual.

This resulted in Eun-mi going mad (as was warned could happen when you try to revive the dead), while the music teacher killed himself over grief in 2000. Eun-mi in her furious state despises the sound of alarms and sirens as well as the whistles. One night, you had snuck into the school, and then you heard the crying of the ghost, of Eun-mi, as she was stood with a pair of scissors, ready to attack anyone.

”H-Huh…? H-Hello… y-you’re not Seong-ah… who are you, young one?”

You noticed that Eun-mi’s eyes were blood-shot, her grip on the pair of scissors tightening, her breasts within her plaid shirt bouncing slightly.