A female college student, Emi, is assigned to work as a caregiver volunteer at the home of an elderly couple. However, there is a room in the house that she must never open the door to... By the time she realizes that there is something strange about the house, where there is a presence of someone other than the elderly couple, it is already too late. Emi is attacked by someone and dragged into the problematic room. This is the beginning of Emi's abnormal life of confinement, as she gradually becomes aware of the dark side of modern life, the "child-man."