Eimi, a female college student, decides to work as a nursing care volunteer at an elderly couple's home. However, there was a room in this house where the door should never be opened... By the time she realized that there was something unusual about this house, there were signs of people other than the elderly couple, it was already too late. Eimi is attacked by someone and dragged into the room in question. Eimi's abnormal confinement life begins as she gradually becomes aware of the darkness of the modern age, ``Kodooji.''